FXing Serious wrote on 2025-01-14, 21:57:

Hello, […]
Show full quote

Hello,

Newbie question.... I recently learned that the K6-2 550 I have ends with AGR. Reading through the docs I learned that:

A = package type.
G = Operating Voltage.
R = Maximum Case Temperature.

And since there are several variants like AFX, AHR and so on... I am wondering if there are K6-2 CPUs that are more preferred than others and why? The why is because of the difference I see in Voltage and Case Temp, but I am not entirely sure what they mean as far as performance goes. Thanks!

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 to squeeze it, to make it go higher towards 600 MHz and beyond, for that, that is, if you want to overclock (quite safe), the K6-2-3+ are ideal, which are the same CPU with full cache (256) or halved (128), I have a K6-2+ 550, and you can easily bring up to 600 or even something more, obviously 🙄 it also depends on the goodness of the CPU or the motherboard.
Going back to the K6-2, I prefer the CXTs, because they have a multi 6X, and I can put them on motherboards with Intel chipsets and switching controllers.
I also like the strange versions, such as the 380, the 433 and the 533, with their respective FSB 95 96.2 and 97.

PC@LIVE wrote on 2025-01-14, 22:33:

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 […]
Show full quote

FXing Serious wrote on 2025-01-14, 21:57:

Hello, […]
Show full quote

Hello,

Newbie question.... I recently learned that the K6-2 550 I have ends with AGR. Reading through the docs I learned that:

A = package type.
G = Operating Voltage.
R = Maximum Case Temperature.

And since there are several variants like AFX, AHR and so on... I am wondering if there are K6-2 CPUs that are more preferred than others and why? The why is because of the difference I see in Voltage and Case Temp, but I am not entirely sure what they mean as far as performance goes. Thanks!

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 to squeeze it, to make it go higher towards 600 MHz and beyond, for that, that is, if you want to overclock (quite safe), the K6-2-3+ are ideal, which are the same CPU with full cache (256) or halved (128), I have a K6-2+ 550, and you can easily bring up to 600 or even something more, obviously 🙄 it also depends on the goodness of the CPU or the motherboard.
Going back to the K6-2, I prefer the CXTs, because they have a multi 6X, and I can put them on motherboards with Intel chipsets and switching controllers.
I also like the strange versions, such as the 380, the 433 and the 533, with their respective FSB 95 96.2 and 97.

Don’t forget the 475

rmay635703 wrote on 2025-01-14, 23:52:

PC@LIVE wrote on 2025-01-14, 22:33:

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 […]
Show full quote

FXing Serious wrote on 2025-01-14, 21:57:

Hello, […]
Show full quote

Hello,

Newbie question.... I recently learned that the K6-2 550 I have ends with AGR. Reading through the docs I learned that:

A = package type.
G = Operating Voltage.
R = Maximum Case Temperature.

And since there are several variants like AFX, AHR and so on... I am wondering if there are K6-2 CPUs that are more preferred than others and why? The why is because of the difference I see in Voltage and Case Temp, but I am not entirely sure what they mean as far as performance goes. Thanks!

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 to squeeze it, to make it go higher towards 600 MHz and beyond, for that, that is, if you want to overclock (quite safe), the K6-2-3+ are ideal, which are the same CPU with full cache (256) or halved (128), I have a K6-2+ 550, and you can easily bring up to 600 or even something more, obviously 🙄 it also depends on the goodness of the CPU or the motherboard.
Going back to the K6-2, I prefer the CXTs, because they have a multi 6X, and I can put them on motherboards with Intel chipsets and switching controllers.
I also like the strange versions, such as the 380, the 433 and the 533, with their respective FSB 95 96.2 and 97.

Don’t forget the 475

Yes Thanks ☺️ for reminding me, however the strangest of all, which I don't have unfortunately 😣, it's the 337 with FSB 75, it was probably an ideal replacement for PC with Cyrix or IBM CPUs, but it was 2.2V unlike the Cyrix that had 2.8V, and a lower frequency, the 333 was actually a 262 MHz, something that AMD didn't do anymore after the K5, even if later with the Athlon XP it was again.

I would like to have K6-2+ 570MHz, but i also dont have K6-2 550Mhz. All AMD cpus-s from 400MHz can be used with K6init.
Also i would like to have more K6-III/III+ cpus, i have only one K6-III+ 400MHz, it can be easly underclock and OC to 600MHz.

PC@LIVE wrote on 2025-01-14, 22:33:

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 […]
Show full quote

FXing Serious wrote on 2025-01-14, 21:57:

Hello, […]
Show full quote

Hello,

Newbie question.... I recently learned that the K6-2 550 I have ends with AGR. Reading through the docs I learned that:

A = package type.
G = Operating Voltage.
R = Maximum Case Temperature.

And since there are several variants like AFX, AHR and so on... I am wondering if there are K6-2 CPUs that are more preferred than others and why? The why is because of the difference I see in Voltage and Case Temp, but I am not entirely sure what they mean as far as performance goes. Thanks!

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 to squeeze it, to make it go higher towards 600 MHz and beyond, for that, that is, if you want to overclock (quite safe), the K6-2-3+ are ideal, which are the same CPU with full cache (256) or halved (128), I have a K6-2+ 550, and you can easily bring up to 600 or even something more, obviously 🙄 it also depends on the goodness of the CPU or the motherboard.
Going back to the K6-2, I prefer the CXTs, because they have a multi 6X, and I can put them on motherboards with Intel chipsets and switching controllers.
I also like the strange versions, such as the 380, the 433 and the 533, with their respective FSB 95 96.2 and 97.

Thank you for your reply! Very informative. What about the different models of 550? Do these differences in voltages help you squeeze in terms of overclocking?

FXing Serious wrote on 2025-01-15, 16:35:

PC@LIVE wrote on 2025-01-14, 22:33:

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 […]
Show full quote

FXing Serious wrote on 2025-01-14, 21:57:

Hello, […]
Show full quote

Hello,

Newbie question.... I recently learned that the K6-2 550 I have ends with AGR. Reading through the docs I learned that:

A = package type.
G = Operating Voltage.
R = Maximum Case Temperature.

And since there are several variants like AFX, AHR and so on... I am wondering if there are K6-2 CPUs that are more preferred than others and why? The why is because of the difference I see in Voltage and Case Temp, but I am not entirely sure what they mean as far as performance goes. Thanks!

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 to squeeze it, to make it go higher towards 600 MHz and beyond, for that, that is, if you want to overclock (quite safe), the K6-2-3+ are ideal, which are the same CPU with full cache (256) or halved (128), I have a K6-2+ 550, and you can easily bring up to 600 or even something more, obviously 🙄 it also depends on the goodness of the CPU or the motherboard.
Going back to the K6-2, I prefer the CXTs, because they have a multi 6X, and I can put them on motherboards with Intel chipsets and switching controllers.
I also like the strange versions, such as the 380, the 433 and the 533, with their respective FSB 95 96.2 and 97.

Thank you for your reply! Very informative. What about the different models of 550? Do these differences in voltages help you squeeze in terms of overclocking?

Generally chips with the highest case temperature and lowest voltage are the easiest to be stable or overclock.

550’s in “normal “ k6-2 form are almost always 2.3 volts and rarely tolerant of the max temperatures.

PC@LIVE wrote on 2025-01-15, 11:53:

rmay635703 wrote on 2025-01-14, 23:52:

PC@LIVE wrote on 2025-01-14, 22:33:

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 to squeeze it, to make it go higher towards 600 MHz and beyond, for that, that is, if you want to overclock (quite safe), the K6-2-3+ are ideal, which are the same CPU with full cache (256) or halved (128), I have a K6-2+ 550, and you can easily bring up to 600 or even something more, obviously 🙄 it also depends on the goodness of the CPU or the motherboard.
Going back to the K6-2, I prefer the CXTs, because they have a multi 6X, and I can put them on motherboards with Intel chipsets and switching controllers.
I also like the strange versions, such as the 380, the 433 and the 533, with their respective FSB 95 96.2 and 97.

Don’t forget the 475

Yes Thanks ☺️ for reminding me, however the strangest of all, which I don't have unfortunately 😣, it's the 337 with FSB 75, it was probably an ideal replacement for PC with Cyrix or IBM CPUs, but it was 2.2V unlike the Cyrix that had 2.8V, and a lower frequency, the 333 was actually a 262 MHz, something that AMD didn't do anymore after the K5, even if later with the Athlon XP it was again.

Yeah oddly most of the 75mhz FSB k6-2’s came as OEM IBM parts so I guess that logic makes sense .

It reminds me of AMDs line of gimped 66mhz FSB only chips while 100mhz FSB were common.

rmay635703 wrote on 2025-01-15, 16:48:

FXing Serious wrote on 2025-01-15, 16:35:

PC@LIVE wrote on 2025-01-14, 22:33:

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 to squeeze it, to make it go higher towards 600 MHz and beyond, for that, that is, if you want to overclock (quite safe), the K6-2-3+ are ideal, which are the same CPU with full cache (256) or halved (128), I have a K6-2+ 550, and you can easily bring up to 600 or even something more, obviously 🙄 it also depends on the goodness of the CPU or the motherboard.
Going back to the K6-2, I prefer the CXTs, because they have a multi 6X, and I can put them on motherboards with Intel chipsets and switching controllers.
I also like the strange versions, such as the 380, the 433 and the 533, with their respective FSB 95 96.2 and 97.

Thank you for your reply! Very informative. What about the different models of 550? Do these differences in voltages help you squeeze in terms of overclocking?

Generally chips with the highest case temperature and lowest voltage are the easiest to be stable or overclock.

550’s in “normal “ k6-2 form are almost always 2.3 volts and rarely tolerant of the max temperatures.

Okay I get it now. I can see why the previous poster said "K6-2-3+ are ideal". Thanks!

For me, the AMD K6-III+ 550ACR would be most desirable.

I arrived at that because:

• Package Type: "A" because that's really the only game in town for things that are not soldered down.
• Higher clock speed is almost always more better, but from model to model, K6-III+ = K6-III = K6-2+ @ 10% higher frequency = K6-2 @ 25% higher frequency
• Operating Voltage: Lowest that my board supports, because lower power usually means less stress on the MoBo, less cooling, and maybe more over clocking headroom, if that's your game. My board supports 2.0V
• Case Temperature: Higher is better, because it suggests that the CPU is more rugged, but this might be more of a tie breaker than a game changer

Package Type A = 321-pin CPGA

Operating Voltage: (Data sheet usually lists them as +/- 1V or +/- 0.5V )
U:1.5V
T:1.6V
P: 1.7V
N: 1.8V
M: 1.9V
C: 2.0V
D:2.1V
F: 2.2V
G:2.3V
H: 2.4V
L: 2.9V
(Older K6) N: 3.2V

Case Temperature:
Q: <=60C
X: <=65C
R: <=70C
K: <=80C
Z: <=85C

Old Benchmarks that have K6-2 vs K6-2+ vs K6-III

https://www.tomshardware.com/reviews/benchmar … hon,590-23.html

https://www.anandtech.com/show/707/super7-upg … -3-processors/9

rmay635703 wrote on 2025-01-14, 23:52:

PC@LIVE wrote on 2025-01-14, 22:33:

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 […]
Show full quote

FXing Serious wrote on 2025-01-14, 21:57:

Hello, […]
Show full quote

Hello,

Newbie question.... I recently learned that the K6-2 550 I have ends with AGR. Reading through the docs I learned that:

A = package type.
G = Operating Voltage.
R = Maximum Case Temperature.

And since there are several variants like AFX, AHR and so on... I am wondering if there are K6-2 CPUs that are more preferred than others and why? The why is because of the difference I see in Voltage and Case Temp, but I am not entirely sure what they mean as far as performance goes. Thanks!

So if we talk about K6-2, so excluding the K6-3 and the K6-2-3+, the 550 is the fastest, but I think it's also very difficult 😩 to squeeze it, to make it go higher towards 600 MHz and beyond, for that, that is, if you want to overclock (quite safe), the K6-2-3+ are ideal, which are the same CPU with full cache (256) or halved (128), I have a K6-2+ 550, and you can easily bring up to 600 or even something more, obviously 🙄 it also depends on the goodness of the CPU or the motherboard.
Going back to the K6-2, I prefer the CXTs, because they have a multi 6X, and I can put them on motherboards with Intel chipsets and switching controllers.
I also like the strange versions, such as the 380, the 433 and the 533, with their respective FSB 95 96.2 and 97.

Don’t forget the 475

Correct, I have a 475. It came out of a Toshiba laptop.

douglar wrote on 2025-01-15, 21:10:

Old Benchmarks that have K6-2 vs K6-2+ vs K6-III

https://www.tomshardware.com/reviews/benchmar … hon,590-23.html

https://www.anandtech.com/show/707/super7-upg … -3-processors/9

So it seems to me that at the time, the "+" chips were mobile and was not available for the general public right?

douglar wrote on 2025-01-15, 19:35:

For me, the AMD K6-III+ 550ACR would be most desirable. […]
Show full quote

For me, the AMD K6-III+ 550ACR would be most desirable.

I arrived at that because:

• Package Type: "A" because that's really the only game in town for things that are not soldered down.
• Higher clock speed is almost always more better, but from model to model, K6-III+ = K6-III = K6-2+ @ 10% higher frequency = K6-2 @ 25% higher frequency
• Operating Voltage: Lowest that my board supports, because lower power usually means less stress on the MoBo, less cooling, and maybe more over clocking headroom, if that's your game. My board supports 2.0V
• Case Temperature: Higher is better, because it suggests that the CPU is more rugged, but this might be more of a tie breaker than a game changer

Package Type A = 321-pin CPGA

Operating Voltage: (Data sheet usually lists them as +/- 1V or +/- 0.5V )
U:1.5V
T:1.6V
P: 1.7V
N: 1.8V
M: 1.9V
C: 2.0V
D:2.1V
F: 2.2V
G:2.3V
H: 2.4V
L: 2.9V
(Older K6) N: 3.2V

Case Temperature:
Q: <=60C
X: <=65C
R: <=70C
K: <=80C
Z: <=85C

Could you tell me in between these two... which is the "better" chip?

AMD-K6-III/450AFX

Operating Voltage
2.1V–2.3V (Core)
3.135V–3.6V (I/O)

Case
Temperature
0°C–65°C

AMD-K6-III/450AHX

2.3V–2.5V (Core)
3.135V–3.6V (I/O)

Case
Temperature
0°C–65°C

FXing Serious wrote on 2025-01-16, 18:37:

Could you tell me in between these two... which is the "better" chip? […]
Show full quote

douglar wrote on 2025-01-15, 19:35:

For me, the AMD K6-III+ 550ACR would be most desirable. […]
Show full quote

For me, the AMD K6-III+ 550ACR would be most desirable.

I arrived at that because:

• Package Type: "A" because that's really the only game in town for things that are not soldered down.
• Higher clock speed is almost always more better, but from model to model, K6-III+ = K6-III = K6-2+ @ 10% higher frequency = K6-2 @ 25% higher frequency
• Operating Voltage: Lowest that my board supports, because lower power usually means less stress on the MoBo, less cooling, and maybe more over clocking headroom, if that's your game. My board supports 2.0V
• Case Temperature: Higher is better, because it suggests that the CPU is more rugged, but this might be more of a tie breaker than a game changer

Package Type A = 321-pin CPGA

Operating Voltage: (Data sheet usually lists them as +/- 1V or +/- 0.5V )
U:1.5V
T:1.6V
P: 1.7V
N: 1.8V
M: 1.9V
C: 2.0V
D:2.1V
F: 2.2V
G:2.3V
H: 2.4V
L: 2.9V
(Older K6) N: 3.2V

Case Temperature:
Q: <=60C
X: <=65C
R: <=70C
K: <=80C
Z: <=85C

Could you tell me in between these two... which is the "better" chip?

AMD-K6-III/450AFX

Operating Voltage
2.1V–2.3V (Core)
3.135V–3.6V (I/O)

Case
Temperature
0°C–65°C

AMD-K6-III/450AHX

2.3V–2.5V (Core)
3.135V–3.6V (I/O)

Case
Temperature
0°C–65°C

AFX, the 2.4 volt chips were hot running antiques.

FXing Serious wrote on 2025-01-16, 18:37:

Could you tell me in between these two... which is the "better" chip?

AMD-K6-III/450AFX 2.1V–2.3V (Core)
AMD-K6-III/450AHX 2.3V–2.5V (Core)

If your motherboard supports both 2.2V and 2.4V operation, I'd take the AFX because I expect it to run a little cooler and last a little longer, but the chips are in adjoining bins and there's some variance in each bin and the parts are 25 years old, so nothing is guaranteed.

But if your motherboard only supports 2.4V operation, I'd recommend that you take the AHX instead of running the AFX at 2.4V, even though in the back of my mind, I'd have the nagging suspicion that both dies could have been cut from the same wafer, and the AHX is an inferior chip that needed higher voltage to run at the same clock speed, but I can't recommend that anyone run the AFX at 2.4V because that's not what the spec sheet says.

It’s worth noting the 2.4v chips didn’t remain at retail very long and existed mainly just before the 500mhz speed grade released
I would view them as
in house overclocked from the factory.

As AMDs bin rate got better you saw fewer and fewer 2.4 volt examples.

This might be controversial but for me "most desirable" is K6-2 400MHz. Simply because it can run at its rated speed on 66MHz bus. Faster chips require Super7 mobos which are hard to find and sometimes have weird quirks. I'm running my chip on pretty common VIA 585VPX without any issues.

FXing Serious wrote on 2025-01-16, 18:28:

douglar wrote on 2025-01-15, 21:10:

Old Benchmarks that have K6-2 vs K6-2+ vs K6-III

https://www.tomshardware.com/reviews/benchmar … hon,590-23.html

https://www.anandtech.com/show/707/super7-upg … -3-processors/9

So it seems to me that at the time, the "+" chips were mobile and was not available for the general public right?

I first became aware of/interested in the K6-2+ CPUs in the spring of 2001 after reading Oldie Tuning on Tom's Hardware, and in June of 2001 I was able to buy a K6-2+ 475 for something like 30 to 40 dollars from Tiger Direct. AMD may not have been marketing or trying to sell them to the general public, but they weren't hard to find.

Repo Man11 wrote on 2025-01-16, 21:03:

I first became aware of/interested in the K6-2+ CPUs in the spring of 2001 after reading Oldie Tuning on Tom's Hardware, and in June of 2001 I was able to buy a K6-2+ 475 for something like 30 to 40 dollars from Tiger Direct. AMD may not have been marketing or trying to sell them to the general public, but they weren't hard to find.

The chips were getting dumped at low prices and were easy to get. The motherboards that supported them on the other hand were a little harder to find. And sites like amdzone.com per popular helping people find BIOS upgrades to use the chips.