I figure it could probably easily fit a p54c 200 in its place though. Can’t think of a reason it wouldn’t work. Or a k6-2 233 ANR,

But the thing is , I imagine whatever laptop you shoehorned this into you would end up underclocking/undervolting the chip significantly to meet the thermal/power envelope.

Exactly - TDP of the C6-200 is 10.4W, P54CS-200 is 15.5W.

At regular 3.3V you'd have to clock it back to <120MHz to get to similar power levels. But the P54CS is pretty overengineered, so you can probably get away with lower voltage - if the laptop/adapter can deliver it. I don't think the adapter board has full VRM capabilities, so you're dependent on the laptop motherboard here.

At 2.9V you could do at least 150MHz under 10.4W. Question is: would it be worth it? The C6 has terrible floating point performance, but pretty decent ALU. If you want to play Quake, the P54CS would be faster, but for pretty much everything else you'd not be seeing much advantage.

Aside from the optional support for split voltage planes, the difference between So5 and So7 is pin BF1, so multiplier settings for 2.5x and 3.0x . If that pin's not there you'll have fewer options, and you'll not be able to run the P54CS past 133MHz anyway. Looking at the multiplier settings for C6 here on page 4-2, 3x is the same on both CPUs, but the C6 pulls all pins high by default, so it's possible to get 3x on So5 with only BF0 low (from motherboard, i.e. the setting for 1.5x on a Pentium), so without testing you can't say whether BF1 is actively set by motherboard/adapter (which would give you 3x on P54CS as well) or if it's not set by motherboard/adapter; in that the case, you'd get 100MHz with P54CS.

Of course, you can bodge BF settings by connecting the relevant pins on the CPU to VSS/VIO as needed.

As for K6-2, they use 2.2V, so unless that laptop has vastly more voltage options than this, that's out of the question. A K6 would work at 2.9V, but that would burn 20W; it will also work at 3.3V, but then would get even hotter (almost 23W), so way out for a laptop designed for 10W.

Whoa, What is that notebook's model?

Cheers,

dionb wrote on 2025-08-25, 08:19:

Exactly - TDP of the C6-200 is 10.4W, P54CS-200 is 15.5W. […]
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I figure it could probably easily fit a p54c 200 in its place though. Can’t think of a reason it wouldn’t work. Or a k6-2 233 ANR,

But the thing is , I imagine whatever laptop you shoehorned this into you would end up underclocking/undervolting the chip significantly to meet the thermal/power envelope.

Exactly - TDP of the C6-200 is 10.4W, P54CS-200 is 15.5W.

At regular 3.3V you'd have to clock it back to <120MHz to get to similar power levels. But the P54CS is pretty overengineered, so you can probably get away with lower voltage - if the laptop/adapter can deliver it. I don't think the adapter board has full VRM capabilities, so you're dependent on the laptop motherboard here.

At 2.9V you could do at least 150MHz under 10.4W. Question is: would it be worth it? The C6 has terrible floating point performance, but pretty decent ALU. If you want to play Quake, the P54CS would be faster, but for pretty much everything else you'd not be seeing much advantage.

Aside from the optional support for split voltage planes, the difference between So5 and So7 is pin BF1, so multiplier settings for 2.5x and 3.0x . If that pin's not there you'll have fewer options, and you'll not be able to run the P54CS past 133MHz anyway. Looking at the multiplier settings for C6 here on page 4-2, 3x is the same on both CPUs, but the C6 pulls all pins high by default, so it's possible to get 3x on So5 with only BF0 low (from motherboard, i.e. the setting for 1.5x on a Pentium), so without testing you can't say whether BF1 is actively set by motherboard/adapter (which would give you 3x on P54CS as well) or if it's not set by motherboard/adapter; in that the case, you'd get 100MHz with P54CS.

Of course, you can bodge BF settings by connecting the relevant pins on the CPU to VSS/VIO as needed.

As for K6-2, they use 2.2V, so unless that laptop has vastly more voltage options than this, that's out of the question. A K6 would work at 2.9V, but that would burn 20W; it will also work at 3.3V, but then would get even hotter (almost 23W), so way out for a laptop designed for 10W.

I suspect that the card likely has bf 0/1 routed somewhere. but no worries if not, I have this 😀
Socket 5/7/SS7 (Processor Shim) Tweaker (Released)

fun to talk, but currently I don't have a laptop for this. fun to ponder though.