K6 350MHz? I'm fairly sure you're talking about a K6-2 350MHz.
Iirc K6 went up to 300MHz.

and whether it's a K6 2 or a K6 2+.

K6-2+ has L2 cache while K6-2 doesn't, so you should be able to distinguish between the 2.
Also K6-2+ had received a die-shrink compared to the 'ordinary' K6-2 (and later K6).

It went a little like this (cutting some corners here to make a point):
AMD released the K6. This version went up to 233MHz
Then they gave the K6 a die-shrink and clocked this one up to 300MHz (usually with 66MHz FSB).
Then they made K6-2 which is essentially a tweaked K6 (imo the difference isn't very large), of which there were several revisions. This CPU went up to 550MHz or 570MHz or so.

Then they added L2 cache to the K6-2 and named that CPU the K6-III. This CPU was a bit harder to clock up so it got stuck at 450MHz to perhaps 500MHz

Then they gave that CPU a die-shrink (along with some minor tweaks to make it more suitable for laptops) and those were the K6-III+
Some of these CPUs got half their L2 cache disabled and AMD named those CPUs K6-2+
It's the + CPUs that are the best overclockers, but not all ss7 boards will support them (or at least not without some modding).

Yes you've got the motherboard level multiplier control in CMOS setup there, otherwise known as "Soft Menu", BIOS and motherboard implemented, I don't know if there are external utilities that can manipulate motherboards in DOS or windows... though later softFSB utils can talk to the clock chip. So your disadvantage there is having to reboot into setup to change the speed, whereas with a 2+ or 3+ you can change it from the DOS prompt. There is a little more to "on the fly" multi changing than just having the pins triggered, as I believe the "legal" method is to stick the CPU in a power management state briefly while changing otherwise it skips clock cycles or doesn't sync up and trips over it's own feet. i.e. crashes.

Anyway, you're seeing 2x as unavailable as on late K6, K6-2 and K6-3 it's remapped to 6x, and most of the slower speed ones are incapable of running fast enough to take advantage of 6x multi, the pre CXT cores in particular have a wall below 400. Possibly there's a way to force it on, and run at 6x50 but there's not a lot of point.

Tetrium wrote on 2023-02-10, 18:57:

K6 350MHz? I'm fairly sure you're talking about a K6-2 350MHz.
Iirc K6 went up to 300MHz.
K6-2+ has L2 cache while K6-2 doesn't, so you should be able to distinguish between the 2.

Yeah, thats why I just wrote K6, as I got no idea which one it is exactly.
But isn't L2 cache motherboard Cache?
(mentioned here: https://youtu.be/fcAqRbFFQPU?t=1428 )

On Bootup it shows:
External Cache: 1024KB
Cache Type: Pipelined Burst

And I can enable/disable internal and external cache in the BIOS. But does that mean it's a K6 2+?

So your disadvantage there is having to reboot into setup to change the speed, whereas with a 2+ or 3+ you can change it from the DOS prompt

Ah, alrighty. Well, I can live with that then ^^

Anyway, you're seeing 2x as unavailable as on late K6, K6-2 and K6-3 it's remapped to 6x, and most of the slower speed ones are incapable of running fast enough to take advantage of 6x multi, the pre CXT cores in particular have a wall below 400. Possibly there's a way to force it on, and run at 6x50 but there's not a lot of point.

My goal is actually to make it as slow as possible. ^^
The 166 Mhz are probably fine, but I might get into a situation where I need a slower CPU, so going down to 2X60Mhz would be nice.
Is there any danger of just setting it to 2.2V 2X60Hz and give it a try?
I also got an option of 1.5/3.5 but I am not sure what that means. Considering it is used for the 350Mhz setting for a x 3.5 multiplication, I guess it will also multiply any other value with 3.5 and not with 1.5

Kordanor wrote on 2023-02-10, 20:27:

Tetrium wrote on 2023-02-10, 18:57:

K6 350MHz? I'm fairly sure you're talking about a K6-2 350MHz.
Iirc K6 went up to 300MHz.
K6-2+ has L2 cache while K6-2 doesn't, so you should be able to distinguish between the 2.

Yeah, thats why I just wrote K6, as I got no idea which one it is exactly.

I get it 🙂

Personally, when the exact subtype is unspecified, I'll write it as K6-? or K6-X or something 😜

But isn't L2 cache motherboard Cache? (mentioned here: https://youtu.be/fcAqRbFFQPU?t=1428 ) […]
Show full quote

But isn't L2 cache motherboard Cache?
(mentioned here: https://youtu.be/fcAqRbFFQPU?t=1428 )

On Bootup it shows:
External Cache: 1024KB
Cache Type: Pipelined Burst

And I can enable/disable internal and external cache in the BIOS. But does that mean it's a K6 2+?

It means it is (with highly likely bordering on certainly) an ordinary K6-2 as with the K6-III and K6+ chips, the mnotherboard L2 cache should become L3 cache.

K6-III was (here in The Netherlands at least) way more uncommon than the K6-2 and K6 CPUs. K6+ I had to buy from the internet to get some as I never found any of those in the wild.

Can you download cpu-z vintage edition, copy it to this computer and run it?

The + cpus are nice that you can set the multiplier through software.

The k6-3 has 256k of cache on the cpu, the 2+ also had 256k but 128k was disabled (you can possibly enable it), and the 3+ has 256k

As far as I know software setting the multipler doesn’t work on k6-3 non plus or any other k6/k5

It’s also worth noting that no other socket 5/7/ss7 cpu has onboard cache. Only k6-3,2+,3+

-It is possible that a full cache disabled k6-2 exists but no such example has come forward. There is a jumper on 2+\3+ cpus for fully disabling cache. I kinda doubt that any actually exist.

The 1024k you are seeing is on the motherboard.

You most likely have a plain old k6-2

Cpu-z can tell you more. Or chkcpu in dos.

dont have the PC so far that Windows 98 is up, so I used chkcpu. but it essentially just reads whatever is set up in bios it seems. I am currently still fighting with an issue, that it keeps telling my that the battery is low, which it is not. And so it forgot the cpu again. I kept that first report with the "wrong CPU" in. I then changed it in bios to the 350mhz cpu and ran it again.
Here is the complete log:

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CXT 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 151.3 MHz
Clock Multiplier : Available only in Real Mode!
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D processor
CPU-ID Signature : 00058C
|||||+- Stepping or sub-model no.
||||+- Model: Indicates CPU Model and 486 L1 cache mode
|||+- Family: 4=486, Am5x86, Cx5x86
||| 5=Pentium, Nx586, Cx6x86, K5/K6, C6, mP6
||| 6=PentiumPro/II/III, CxMII/III, Athlon, C3
||| F=Pentium4, Athlon64
||+- Type: 0=Standard, 1=Overdrive, 2=2nd Dual Pentium
|+- Ext. Model: Extends the Base Model to an 8-bit value
+- Ext. Family: Extends the Base Family value
Current CPU mode : Virtual
Internal (L1) cache : Enabled in Write-Back mode

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CXT 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 151.1 MHz
Clock Multiplier : Available only in Real Mode!
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D processor
CPU-ID Signature : 00058C
|||||+- Stepping or sub-model no.
||||+- Model: Indicates CPU Model and 486 L1 cache mode
|||+- Family: 4=486, Am5x86, Cx5x86
||| 5=Pentium, Nx586, Cx6x86, K5/K6, C6, mP6
||| 6=PentiumPro/II/III, CxMII/III, Athlon, C3
||| F=Pentium4, Athlon64
||+- Type: 0=Standard, 1=Overdrive, 2=2nd Dual Pentium
|+- Ext. Model: Extends the Base Model to an 8-bit value
+- Ext. Family: Extends the Base Family value
Current CPU mode : Virtual
Internal (L1) cache : Enabled in Write-Back mode

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CXT 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 151.3 MHz
Clock Multiplier : Available only in Real Mode!
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D processor
CPU-ID Signature : 00058C
CPU Features : Floating-Point Unit on chip : Yes
Virtual Mode Extensions : Yes
Time Stamp Counter : Yes
Instr set extensions: MMX, 3DNow!
Current CPU mode : Virtual
Internal (L1) cache : Enabled in Write-Back mode
Size of L1 cache : 64 KB

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
Debug Mode!
Running DOS version : 6.22
Current CPU mode : Virtual

CPUID Level: EAX: EBX: ECX: EDX:
00000000 00000001 68747541 444D4163 69746E65
00000001 0000058C 00000000 00000000 008021BF

80000000 80000005 00000000 00000000 00000000
80000001 0000068C 00000000 00000000 808029BF
80000002 2D444D41 7428364B 3320296D 72702044
80000003 7365636F 00726F73 00000000 00000000
80000004 00000000 00000000 00000000 00000000
80000005 00000000 02800140 20020220 20020220

AMD K6-2 151MHz

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CXT 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 352.7 MHz
Clock Multiplier : Available only in Real Mode!
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D processor
CPU-ID Signature : 00058C
|||||+- Stepping or sub-model no.
||||+- Model: Indicates CPU Model and 486 L1 cache mode
|||+- Family: 4=486, Am5x86, Cx5x86
||| 5=Pentium, Nx586, Cx6x86, K5/K6, C6, mP6
||| 6=PentiumPro/II/III, CxMII/III, Athlon, C3
||| F=Pentium4, Athlon64
||+- Type: 0=Standard, 1=Overdrive, 2=2nd Dual Pentium
|+- Ext. Model: Extends the Base Model to an 8-bit value
+- Ext. Family: Extends the Base Family value
Current CPU mode : Virtual
Internal (L1) cache : Enabled in Write-Back mode

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CXT 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 353.5 MHz
Clock Multiplier : Available only in Real Mode!
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D processor
CPU-ID Signature : 00058C
|||||+- Stepping or sub-model no.
||||+- Model: Indicates CPU Model and 486 L1 cache mode
|||+- Family: 4=486, Am5x86, Cx5x86
||| 5=Pentium, Nx586, Cx6x86, K5/K6, C6, mP6
||| 6=PentiumPro/II/III, CxMII/III, Athlon, C3
||| F=Pentium4, Athlon64
||+- Type: 0=Standard, 1=Overdrive, 2=2nd Dual Pentium
|+- Ext. Model: Extends the Base Model to an 8-bit value
+- Ext. Family: Extends the Base Family value
Current CPU mode : Virtual
Internal (L1) cache : Enabled in Write-Back mode

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CXT 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 352.7 MHz
Clock Multiplier : Available only in Real Mode!
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D processor
CPU-ID Signature : 00058C
CPU Features : Floating-Point Unit on chip : Yes
Virtual Mode Extensions : Yes
Time Stamp Counter : Yes
Instr set extensions: MMX, 3DNow!
Current CPU mode : Virtual
Internal (L1) cache : Enabled in Write-Back mode
Size of L1 cache : 64 KB

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
Debug Mode!
Running DOS version : 6.22
Current CPU mode : Virtual

CPUID Level: EAX: EBX: ECX: EDX:
00000000 00000001 68747541 444D4163 69746E65
00000001 0000058C 00000000 00000000 008021BF

80000000 80000005 00000000 00000000 00000000
80000001 0000068C 00000000 00000000 808029BF
80000002 2D444D41 7428364B 3320296D 72702044
80000003 7365636F 00726F73 00000000 00000000
80000004 00000000 00000000 00000000 00000000
80000005 00000000 02800140 20020220 20020220

AMD K6-2 353MHz

So from that it seems like it indeed is a K6-2 if it is trustworthy

Hi Kordanor,

I made the CHKCPU utility to have an independent check on the CPU speed, and the FSB and multiplier settings, so CHKCPU is only using data directly from the CPU and doesn’t use any BIOS data.

Yes, you definitely have a regular K6-2, but with the improved Chomper eXTended core. That is why CHKCPU indicates it as a K6-2CXT. This K6-2 model has the x2 multiplier remapped to x6, so the lowest available multiplier is x2.5.

From your CHKCPU report I see you are running the CPU in Virtual mode, probably because you load EMM386.EXE in CONFIG.SYS.
When you run the CPU in Real mode, CHKCPU will show you the multiplier and FSB speed, so you have a direct check on the BIOS settings.
Just remove the EMM386 line from CONFIG.SYS (or put REM at the beginning of the EMM386 line to make it a Remark line, so DOS ignores the command behind it) to get Real mode.

Thanks for sending the whole CHKCPU report, but for your purpose the Chkcpu /v command only should tell you what you want to know.
In Real mode it should look like this:

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CXT 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 350.7 MHz (using internal Time Stamp Counter)
Clock Multiplier : 3.5
Bus clock speed : 100.2 MHz
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D Processor
CPU-ID Signature : 00058C
CPU Features : Floating-Point Unit on chip : Yes
Virtual Mode Extensions : Yes
Time Stamp Counter : Yes
Cool'n'Quiet support : Yes
Instr set extensions: MMX, 3DNow!
Current CPU mode : Real
Internal (L1) cache : Enabled in Write-Back mode
Size of L1 cache : 64 KB

Jan

Chkcpu wrote on 2023-02-11, 15:13:

Hi Kordanor, […]
Show full quote

Hi Kordanor,

I made the CHKCPU utility to have an independent check on the CPU speed, and the FSB and multiplier settings, so CHKCPU is only using data directly from the CPU and doesn’t use any BIOS data.

Yes, you definitely have a regular K6-2, but with the improved Chomper core. That is why CHKCPU indicates it as a K6-2CXT. This K6-2 model has the x2 multiplier remapped to x6, so the lowest available multiplier is x2.5.

From your CHKCPU report I see you are running the CPU in Virtual mode, probably because you load EMM386.EXE in CONFIG.SYS.
When you run the CPU in Real mode, CHKCPU will show you the multiplier and FSB speed, so you have a direct check on the BIOS settings.
Just remove the EMM386 line from CONFIG.SYS (or put REM at the beginning of the EMM386 line to make it a Remark line, so DOS ignores the command behind it) to get Real mode.

Thanks for sending the whole CHKCPU report, but for your purpose the Chkcpu /v command only should tell you what you want to know.
In Real mode it should look like this:

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CTX 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 350.7 MHz (using internal Time Stamp Counter)
Clock Multiplier : 3.5
Bus clock speed : 100.2 MHz
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D Processor
CPU-ID Signature : 00058C
CPU Features : Floating-Point Unit on chip : Yes
Virtual Mode Extensions : Yes
Time Stamp Counter : Yes
Cool'n'Quiet support : Yes
Instr set extensions: MMX, 3DNow!
Current CPU mode : Real
Internal (L1) cache : Enabled in Write-Back mode
Size of L1 cache : 64 KB

Jan

Hey Jan, I would be curious to know if you think you can tell the difference between a k6-2+/3+ with cache disabled on cpu resistor and a k6-2

Can you check out the 3+ mod thread early on people experimented with this and noted the hardware IDs when doing so

If your utility can tell the difference it would be cool to add the note to your program, maybe with time some may pop up disabled?

Re: SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod

Chkcpu wrote on 2023-02-11, 15:13:

Hi Kordanor, […]
Show full quote

Hi Kordanor,

I made the CHKCPU utility to have an independent check on the CPU speed, and the FSB and multiplier settings, so CHKCPU is only using data directly from the CPU and doesn’t use any BIOS data.

Yes, you definitely have a regular K6-2, but with the improved Chomper eXTended core. That is why CHKCPU indicates it as a K6-2CXT. This K6-2 model has the x2 multiplier remapped to x6, so the lowest available multiplier is x2.5.

From your CHKCPU report I see you are running the CPU in Virtual mode, probably because you load EMM386.EXE in CONFIG.SYS.
When you run the CPU in Real mode, CHKCPU will show you the multiplier and FSB speed, so you have a direct check on the BIOS settings.
Just remove the EMM386 line from CONFIG.SYS (or put REM at the beginning of the EMM386 line to make it a Remark line, so DOS ignores the command behind it) to get Real mode.

Thanks for sending the whole CHKCPU report, but for your purpose the Chkcpu /v command only should tell you what you want to know.
In Real mode it should look like this:

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CXT 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 350.7 MHz (using internal Time Stamp Counter)
Clock Multiplier : 3.5
Bus clock speed : 100.2 MHz
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D Processor
CPU-ID Signature : 00058C
CPU Features : Floating-Point Unit on chip : Yes
Virtual Mode Extensions : Yes
Time Stamp Counter : Yes
Cool'n'Quiet support : Yes
Instr set extensions: MMX, 3DNow!
Current CPU mode : Real
Internal (L1) cache : Enabled in Write-Back mode
Size of L1 cache : 64 KB

Jan

Thanks for dropping by! Didnt realize that tool was made by a community member. 😀
So the CPU will not allow for x 1.5 and 2, which the board would support in theory? Is there any list regarding what CPU can do what? Don't necessarily need to change it during runtime, but it would be nice to know which CPU would provide the slowest result.
Unfortunately pages like cpu-world only show the maximum possible multiplier, which for my case doenst matter all too much. (though I don't know if there is a real need to go below 2.5 x 66 Mhz either, seeing that Phil in his video used 133 Mhz with disabled cache to play games made for 386.

For completion I will run the test again as you instructed, but will need to wait for about a week. ( I just desoldered the battery holder, which apparently was broken and need to wait till the new one arrived and is soldered in and I hope I dont break anything doing so.)

Many cyrix cpus support a 1x multi. The fastest that does is the mII 2.9v 366. 2.2v cores do not support it.

The fastest to support 1.5x I’m a little fuzzy on but probably looking at a pentium non mmx 200 there would be easiest to find.

2x, fastest would probably be the fastest first gen k6 that mapped 2x to 2x and not to 6x
I believe you can set 2x on k6-3+ via software, but not via hardware. (Would have to double check) a cyrix 400 or 433 Re: Cyrix 400gp multiplier settings

Most of the fast cpus support 2.5x and above up to their max aupported multiplier.

The motherboard is simply pulling registers on the cpu pins high and low. It is the cpu that has the multiplier not the motherboard.

There are four pins at play,

Bf0
Bf1
Bf2 amd/cyrix-st-ibm/idt/rise
Bf2 intel

Bf2 for the different mfgs is in two locations. Not many motherboards support the intel bf2 and it was only implemented on tillamook.

Kordanor wrote on 2023-02-11, 17:40:

though I don't know if there is a real need to go below 2.5 x 66 Mhz either, seeing that Phil in his video used 133 Mhz with disabled cache to play games made for 386.

The only reason to go below 2.5 x 66 MHz is to play games made for 8088/8086 CPUs but this is better served on a XT-class computer with proper CGA video card (Phil doesn't talk about that era at all). You're very unlikely to play them though.

Alright, thanks I should be golden then 😀
Slowest games I'll probably play are likely from 89/90, for even older stuff, I'd rather use my C64.

Tetrium wrote on 2023-02-10, 19:04:

It went a little like this (cutting some corners here to make a point): AMD released the K6. This version went up to 233MHz Then […]
Show full quote

It went a little like this (cutting some corners here to make a point):
AMD released the K6. This version went up to 233MHz
Then they gave the K6 a die-shrink and clocked this one up to 300MHz (usually with 66MHz FSB).
Then they made K6-2 which is essentially a tweaked K6 (imo the difference isn't very large), of which there were several revisions. This CPU went up to 550MHz or 570MHz or so.

Well, 3DNow was a kinda remarkable feature of the K6-2?

H3nrik V! wrote on 2023-02-11, 20:25:

Tetrium wrote on 2023-02-10, 19:04:

It went a little like this (cutting some corners here to make a point): AMD released the K6. This version went up to 233MHz Then […]
Show full quote

It went a little like this (cutting some corners here to make a point):
AMD released the K6. This version went up to 233MHz
Then they gave the K6 a die-shrink and clocked this one up to 300MHz (usually with 66MHz FSB).
Then they made K6-2 which is essentially a tweaked K6 (imo the difference isn't very large), of which there were several revisions. This CPU went up to 550MHz or 570MHz or so.

Well, 3DNow was a kinda remarkable feature of the K6-2?

Yes, Quake II was the most prominent one where AMD made a version using the 3DNow! instructions to improve performance. nVidia and 3dfx used them as well for optimizations in their drivers. Another notable difference is with the CXT revision of the K6-2 which supports write combining (two MTRRs) that can boost performance in higher resolutions.

All of these enhancements are included with K6-III and K6plus CPUs.

H3nrik V! wrote on 2023-02-11, 20:25:

Tetrium wrote on 2023-02-10, 19:04:

It went a little like this (cutting some corners here to make a point): AMD released the K6. This version went up to 233MHz Then […]
Show full quote

It went a little like this (cutting some corners here to make a point):
AMD released the K6. This version went up to 233MHz
Then they gave the K6 a die-shrink and clocked this one up to 300MHz (usually with 66MHz FSB).
Then they made K6-2 which is essentially a tweaked K6 (imo the difference isn't very large), of which there were several revisions. This CPU went up to 550MHz or 570MHz or so.

Well, 3DNow was a kinda remarkable feature of the K6-2?

Hypothetically, yes. But not a lot of games seemed to use it.

Makes me curious as to whether AMD charged to advertise with 3DNow logo as there seemed to be more post release patches than games trumpeted as 3DNow enhanced up front.

Sphere478 wrote on 2023-02-11, 16:23:

Hey Jan, I would be curious to know if you think you can tell the difference between a k6-2+/3+ with cache disabled on cpu resis […]
Show full quote

Chkcpu wrote on 2023-02-11, 15:13:

Hi Kordanor, […]
Show full quote

Hi Kordanor,

I made the CHKCPU utility to have an independent check on the CPU speed, and the FSB and multiplier settings, so CHKCPU is only using data directly from the CPU and doesn’t use any BIOS data.

Yes, you definitely have a regular K6-2, but with the improved Chomper core. That is why CHKCPU indicates it as a K6-2CXT. This K6-2 model has the x2 multiplier remapped to x6, so the lowest available multiplier is x2.5.

From your CHKCPU report I see you are running the CPU in Virtual mode, probably because you load EMM386.EXE in CONFIG.SYS.
When you run the CPU in Real mode, CHKCPU will show you the multiplier and FSB speed, so you have a direct check on the BIOS settings.
Just remove the EMM386 line from CONFIG.SYS (or put REM at the beginning of the EMM386 line to make it a Remark line, so DOS ignores the command behind it) to get Real mode.

Thanks for sending the whole CHKCPU report, but for your purpose the Chkcpu /v command only should tell you what you want to know.
In Real mode it should look like this:

CPU Identification utility v1.27.1 (c) 1997-2022 Jan Steunebrink
------------------------------------------------------------------------------
CPU Vendor and Model: AMD K6-2 CTX 300/333/350/366/380/400/450/475/500/533/550
Internal CPU speed : 350.7 MHz (using internal Time Stamp Counter)
Clock Multiplier : 3.5
Bus clock speed : 100.2 MHz
CPU-ID Vendor string: AuthenticAMD
CPU-ID Name string : AMD-K6(tm) 3D Processor
CPU-ID Signature : 00058C
CPU Features : Floating-Point Unit on chip : Yes
Virtual Mode Extensions : Yes
Time Stamp Counter : Yes
Cool'n'Quiet support : Yes
Instr set extensions: MMX, 3DNow!
Current CPU mode : Real
Internal (L1) cache : Enabled in Write-Back mode
Size of L1 cache : 64 KB

Jan

Hey Jan, I would be curious to know if you think you can tell the difference between a k6-2+/3+ with cache disabled on cpu resistor and a k6-2

Can you check out the 3+ mod thread early on people experimented with this and noted the hardware IDs when doing so

If your utility can tell the difference it would be cool to add the note to your program, maybe with time some may pop up disabled?

Re: SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod

Hey Sphere,

I re-read the Re: SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod thread and noticed the unique 05C8 CPUID Signature when disabling the L2 cache on a K6-2+.
This is a unique K6 Model 12 and I agree that a never released processor was created! 😀

These are the K6 models I’m aware of:

K6 Model 6, CPUID 0560, 350nm, 2.9V
K6 Model 7, CPUID 0570, 250nm, 2.2V
K6-2 Model 8, CPUID 0580, 250nm, 2.2V
K6-2CXT Model 8, CPUID 058C, 250nm, 2.2V (has the x2 -> x6 multiplier remap)
K6-III Model 9, CPUID 0590, 250nm, 2.4V (has the x2 -> x6 multiplier remap)
K6-2+ Model 13 (D), CPUID 05D4, 180nm, 2.0V (has the x2 -> x6 multiplier remap)
K6-III+ Model 13 (D), CPUID 05D0, 180nm, 2.0V (has the x2 -> x6 multiplier remap)

And now a K6-2 Model 12 (C), CPUID 05C8, 180nm, 2.0V was created!
Without its L2 cache, not a very useful processor in my view, but curious nonetheless!
Maybe useful afterall to set the K6-2 overclock record. 😉

Note that the K6-2CXT has a 058C CPUID Signature, while the crippled K6-2+ has 05C8. Confusing but quite different. 😉

Cheers, Jan