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Slowing a 440BX based PC

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First post, by gerwin

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Not that it is really necessary, but I would like to configure an intel 440BX based system to run slower. Somewhere in the speed range of a 486-DX2 to a pentium 166. I prefer the 440bx because of speed potential, stability, availability, compatibility, AGP support. And because I know them so well by now.

Here are some idea's that I have tried;
-Normal system config: 660MHz/110FSB. Coppermine Slot-1 CPU.
-CPU Multiplier set to 1.0x in bios.. -> No effect since Coppermines are Multiplier locked internally.
-Slowed down using FSB bios setting: 400MHz/66FSB -> way too fast.
-As above but with L2-cache disabled in the bios -> way to fast.
-As above but with L1+L2 cache disabled in the bios -> way to slow (0.5 fps in system shock).
-Normal config but with L1 cache disabled in the bios -> way to slow (2 fps in system shock).
-moslo v1.5.1 trial version, unfortunately without al the fancy options, but it works quite well.

Here is what I would like to try:
-Buy a mobo with 1.5x multiplier setting and an Intel Pentium II 'Klamath' CPU. As I read these CPU's were not multiplier locked they should be able to run at 100Mhz/66FSB... a good starting point.
-Buy a 533Mhz/133FSB coppermine CPU and set it at 266MHz/66FSB and disable L2 cache. Now that is a very cool running CPU, but still to fast.
-Buy Moslo deluxe and see what options it has, and how they work for me (but how to pay with paypal instead of a creditcard?).
-Somehow put in a tualatin CPU that is faster, then see what speed remains when L1 cache is disabled.

Any suggestions. Would the klamath CPU behave as intended?
Or should I drop the 440BX and go for multiplier unlocked CPU's on any super socket 7 chipset or a 430TX chipset?

Reply 2 of 51, by gerwin

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I tried out Throttle. The description is promising: no TSR, a simple trick to skip an amount of CPU clock cycles, and the processor actually cools down in the unused cycles. This could be a real winner!

On the 440BX I have a selection of 12,5% increments in throttling (a hardware limit). But at first I had some problems, as I could not run a SpeedSys benchmark at any slowdown setting. Now by default Throttle disables the L1 cache, and this does not work well for me, as I already tried that myself, and it just cripples things too much. Fortunately with the '-c' parameter you can use Throttle without disabling the L1 cache. And now at first look it actually behaves as if you changed the CPU clock multiplier. Here are the results, I have to note these somewhere anyway:

SpeedSys CPU benchmarks 440BX Coppermine CPU
@660MHz/110FSB normal: 764
12,5% decrease: 668
25,0% decrease: 573
37,5% decrease: 477
50,0% decrease: 382
62,5% decrease: 286 (Pentium II 233)
75,0% decrease: 190
87,5% decrease: 95 (Pentium 133)
@400MHz/66FSB normal: 465
87,5% decrease: 58
@400MHz/66FSB normal, L2 cache disabled: 465
87,5% decrease: 58

A VIA chipset was told to have double the amount of increments, so I tried things out on a VIA 133A with coppermine CPU. here goes:
@866MHz/133FSB normal: 972
68,50% decrease: 304 (K6-2-266)
75,00% decrease: 243 (<Pentium II 233)
81,25% decrease: 182
87,50% decrease: 121 (>Pentium 133)
93,75% decrease: 60
@433MHz/66FSB normal: 490
81,25% decrease: 91 (<Pentium 133)
87,50% decrease: 61
93,75% decrease: 30 (around 486-66)

Maybe it is too long ago, and I forgot the slowness of my long gone 486, but it is not totally comparable to the SpeedSys benchmark comparisons.
At the last setting (benchm. 30) the Quarantine (Gametek) menu is very slow, the fading of screens is slow, but the actual game plays fine. Tyrian (Epic) is too slow at 30 (even in low detail) and also a bit to slow at 60. Sometimes the music lags a bit. I wonder why the system ain't behaving more like SpeedSys indicated.
My CPU indeed gets alot cooler when using Throttle. 😀

Reply 3 of 51, by gerwin

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So the bottom line is that Throttle is a nice tool, but gives noticeable hickups in the few games that I have tried with it. And therefore it is not the same smooth thing as lowering your CPU clock speed.

I am still very interested in P-II's that allow a multiplier below their default. Now I read somewhere that it might work with Pre-august-1998 Pentium II's.
I dusted of my celeron 300 'SL2YP' and installed it, but it remains at 4.5x66MHz instead of the 3x66MHz that I set. Anyone has a Pentium II to try this?

Reply 4 of 51, by ratfink

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I have a Gigabyte GA-686BX board with an SL356 PII 350 processor, marked (c) 1997.

I tried all different settings for the multiplier [=every combination of the 4 switches] and none of them made any difference to what it booted up as.

It would however boot as a 233MHz, by using the 66MHz bus speed.

Reply 6 of 51, by bestemor

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I do remember reading somewhere in these halls that the PII 233-333mhz(1997/early 1998?) was the last one to have unlocked multipliers.
(the later(P2-333?) with sel.high/low signal lock, fixable via Abit BH6 bios)

Here's some more info (google is your... eh, friend ?, well somtimes)

http://www.computing.net/answers/cpus/pentium … lock/14735.html

http://www.tomshardware.com/forum/161272-29-q … oold-piece-junk
"...there seems to be quite a few unlocked first-gen P2s (Klamath core) floating around. I have two unlocked Klamaths--a 233 and a 300..."

...which I assume are 66mhz only.

http://forums.overclockers.com.au/showthread.php?t=2307

I suppose ALL the 0.35 microns are Klamaths(filter the selection/Mfg tech), and are unlocked (?):
http://processorfinder.intel.com/List.aspx?Pa … m=47&SearchKey=

Any Celeron or Deschutes core are locked completely.
.

Reply 7 of 51, by gerwin

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Thanks, here is what I found,

"The Book of Overclocking" states:
klamath 233 and 266MHz: unlocked multiplier
klamath 300MHz: potentially unlocked multiplier
All deschutes: locked multiplier

But I doubt that last line, as various people talk in detail about early Deschutes 333 and some 350MHz that have an unlocked multiplier. But some mean to put down the multiplier of the 333 whilst increasing the FSB. And therefor prefer it to a 350 MHz CPU. But in that case an unlocked CPU may mean one that only accepts multipliers lower then the default.
source
Deschutes are 2.0 Volt instead of 2.8. It would be nice If I could use a deschutes, they run cooler. At first I thought of getting a 350, but I think chances are better with a 333. Then pick the product numbers with the oldest revision (dA0 or dA1).

I just bought an SL2QF, so I can find out for myself when it arrives 😀

Reply 8 of 51, by Silent Loon

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Mhm.. as I understand you, you are willing to change the cpu if necessary.
(Changing cpus on a Slot1 mobo should be quite easy)
I guess the slowest "original" Slot 1 cpu was the 266mhz Celeron with Covington core, as it has no L2 cache at all. Second slowest (apart of the 300mhz Celeron) might be the PII 233 Klamath, but Klamath tent to get very hot, so I wouldn't care about those 33mhz, and use the 266 Deschutes instead.
If you have a S370 adapter and the mobo acepts Via cpus, I would go for the Via Cyrix 500 with Samuel core, as this cpu is - well - wonderfully slow (and also very cool - a passive heatsink should be enough) It has no L2 cache and in normal operation it competes with something like a K6-2 300mhz or so. Imagine what Throttle or Moslo could do... Only drawback is the standard 100mhz fsb, which might speed up the system in general.

Reply 9 of 51, by retro games 100

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Regarding slot 1 pentium II CPUs (or their Celeron 'cousins'), the ones I have tested had passive heatsinks, but I found even the very slow ones crept up to over 50C in temperature. I got a 12cm Noctua case fan, running at only about 800rpm, almost totally silent, and tied it to the CPU's heatsink with a simple elastic band. The temperature then stayed at about 30C. Still quite hot, but a good improvement.

Reply 10 of 51, by gerwin

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@Silent Loon
Yes I had the celeron 300 running years ago, and tried it again yesterday, it is slow but completely locked. I would prefer one that can be set to a slow mode (100MHz/66, disabled L2 cache) and a fast mode (+-350MHz/100) by adjusting the bios or by changing jumpers. 100MHz is no typo, in theory certain Mobo/CPU combinations can set it like that, and I wanna try that. 😀
I don't consider changing CPU's whenever I wanna run a particular piece of software. I fear it would wear out the connectors.
The Via CPU's are interesting, but much more rare, and often locked. I considered them, but did not feel like studying them any further.

@Retro Games 100
Is it because you obtained mostly server CPU's that they are without fan? I think the slot-1 consumer CPU's are normally fitted with a small fan 5x5cm. The 600MHz coppermine core cpu I have remains sufficiently cool with that. Over time I replaced many of these small fans, until I made small a voltage regulator that runs the 12 Volt fan at 8,5 Volt: Slower and silent.
The one coppermine I would certainly trust running without fan is the 533/133Mhz 1,65V, but set at lower, or half speed. I ordered one of these too. And two inexpensive tualatins 1266/133 1,45V as well. I don't have to get bored 😉

Reply 11 of 51, by retro games 100

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ebay seems to be awash with P2 & P3 CPUs. I spotted this auction (#320328615874), and its photo is shown below. Check out those fins! 😎 If that were my mobo, as mentioned earlier, I'd have a huge slow 'silent' fan tied to it.

I really don't know if my P2 & P3 CPUs are server-based ones or not. I, like you perhaps, just bought 'em cheap on ebay! 😀

tualatins are impressive cpus. I'm glad you won't get bored. Messing about with this old junk is a good hobby. 😀

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Reply 12 of 51, by 2Mourty

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This is incredibly expensive, but with this board you could run a slightly older processor. I didn't know that there was a pentium pro board with the 440bx chipset.

http://cgi.ebay.com/M701-Pentium-Pro-Motherbo … DefaultDomain_0

Reply 13 of 51, by gerwin

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That board does not look like a 440bx board.. the chips have big white markings, which is also uncommon. Maybe the description is wrong?

@ retro games 100
That is a Klamath core processor at 2,8 Volts, these are told to get hot, and it shows. It's the predecessor of the Deschutes core.

Last edited by gerwin on 2009-02-11, 19:56. Edited 1 time in total.

Reply 14 of 51, by prophase_j

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That motherboard was interesting. I seem to remember that you can get a Slotket with socket 8 instead of socket 370 on it. The whole thing isn't too hard to swallow if you figure that the Pentium Pro's are just P6's with a full speed cache and no MMX (Unless it's a PPRO Overdrive).

"Retro Rocket"
Athlon XP-M 2200+ // Epox 8KTA3
Radeon 9800xt // Voodoo2 SLI
Diamond MX300 // SB AWE64 Gold

Reply 15 of 51, by gerwin

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'M701' points to an Intel i440FX based board, whatever that may be... I was also just reading about Socket 8 adapters for Slot-1.

wikipedia:

As Slot 1 motherboards became prevalent, several manufacturers released slockets, such as the Tyan M2020, Asus C-P6S1, Tekram P6SL1 and the Abit KP6, to allow Pentium Pro processors to be used in them. The Intel 440FX chipset explicitly supports both Pentium Pro and Pentium II processors so using a slocket with them is straightforward. However, since the Intel 440BX and later Slot 1 chipsets do not explicitly support the Pentium Pro, the only Socket 8 processor that will usually work with a slocket in such a motherboard is the Pentium II Overdrive, since it is in essence a Pentium II processor.

Reply 16 of 51, by Silent Loon

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gerwin wrote:

@Silent Loon
I don't consider changing CPU's whenever I wanna run a particular piece of software. I fear it would wear out the connectors.
The Via CPU's are interesting, but much more rare, and often locked. I considered them, but did not feel like studying them any further.

Mhm, currently I use an ECS P6BAT-A+. It has both - a Slot1 and a Socket 370, so I could use a Slot1 PII 266 and (I think that's the highest) a P3 800mhz coppermine. It also accepts the Via cpus. Maybe that's an option?
I don't think that the connectors wear out so fast if you don't change the cpu every day... but I admit, it might be somehow inconvenient...

Reply 17 of 51, by retro games 100

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Message to Gerwin:

I am currently testing a 440BX slot 1 mobo, with a Pentium II CPU running at 233mhz. The mobo is running at 66 FSB.

Would you like me to do any tests on this board, in regards to running the DOS slowdown utility called "Throttle"?

Reply 18 of 51, by gerwin

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@Retro games 100
I have nothing in particular to test... although I would like to read other peoples opinion on the Throttle tool. It ruins Tyrian for example. Not that Tyrian requires the tool 😉. I just wondered what percentage of games runs well with Trottle.

@Silent loon
Coppermines go to 1000MHz, and there are two odd 1100 and 1133's
source at CPU World
You can also go for a Tualatin up to 1400 MHz, but that is the unofficial road and a topic on itself.
Interesting that the ECS has both a socket and a slot, I read that you have to keep one empty.

Reply 19 of 51, by Silent Loon

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@gerwin

With "highest" I meant the highest cpu the board can handle. Its limited because of 100mhz fsb and the multiplier. This is an ECS mobo - so don't expect any overclocking or tweaking options. 😉