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Reply 20 of 47, by Kahenraz

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I think a burning question is whether any of these epoxy methods provides any benefit over a thermal tape. I don't know how you could test for this reliably because a thermal probe on the heatsink wouldn't tell you how well of a thermal transfer is occurring.

Linus did a video comparing a proper thermal paste to a thermal adhesive and it was not reassuring.

Reply 21 of 47, by Kahenraz

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I've been speaking with Anthony from Mod Labs and he says that this chip can work up to 85Mhz. The problem with anything higher like 90Mhz isn't the heat necessarily but some time of timing bug that causes glitches as a result of being so far out of spec.

I think 80Mhz is probably fine if cooled passively but you probably want a small fan if you want to push any higher. I found this great little heatsink and fan combo for this. It's meant for a Late Panda but also fits perfectly on the PCX2.

5V for the fan can be tapped from the voltage regulator or from the vias exposed for a larger crystal oscillator if you use a smaller square package.

I got a color laser printer recently from someone who was moving. I don't know if it works but if it does I hope to print a nice PowerVR logo sticker for the heatsink to match the card.

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Reply 23 of 47, by Kahenraz

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That was my goal as well, to find a way to add an active heatsink on a shared slot. This is still too thick even when paired with an ISA card with no components across from the PCX2 chip with this heatsink attached.

The very thin heatsink is about 3.4mm and about 10.4mm with the fan attached. This is not thin enough for a shared PCI/ISA slot.

I bought one of these Cabletron E22XX network cards thinking that it would be thin enough without any components in the way and just empty PCB but it's still not enough.

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Reply 24 of 47, by Warlord

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i would of just made a sandwich out of something and used a set screw to hold the heat sink down and added a fan to the thing to blow from the top. If you are a man with tools and creativity this could be semi professional. Could even add heat pipes. could also add themal pads to the back of the card as well its limitless.

One thing for certain it would take some time to engineer it, but as long as this thread has been up I could of probably engineered it.

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Reply 27 of 47, by retardware

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I am in serious doubt whether such a small heatsink will be sufficient.
In particular if you want to combine it with a fan not directly attached, larger fins are better.
It needs to be quite strong then. Personally I like these small double fans (actually two fans in one, each rotating the opposite direction), using some of these 40mm double fans. They aren't exactly "quiet" at 12V 0.8A though.

Reply 29 of 47, by Doornkaat

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The 'heatsink' on that Lattepanda cooler is more than sufficient for the PCX2 chip.
It is basically a mounting plate for the fan. It only minimally increases surface area, the grooves are mainly meant so the fan can push air somewhere instead of sitting flat on the mounting plate.
The aluminium plate will also act as a heat spreader that'll conduct heat away from the IC in the center a bit better than the plastic package would. Still it is mostly a convenient solution to attach a fan to low TDP chips using thermal tape.

Reply 30 of 47, by JustJulião

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Kahenraz wrote on 2021-09-07, 11:46:
I also have the option to modify a board with either IBM or NEC memory. I don't know which would be more accommodating to an ove […]
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I also have the option to modify a board with either IBM or NEC memory. I don't know which would be more accommodating to an overclock.

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386SX wrote on 2021-09-07, 11:40:

I never overclocked those cards considering how rare they are and how much they already heat up. 😉

I will be careful and I will also be adding a heatsink and a fan to compensate for the added heat.

386SX wrote on 2021-09-07, 11:40:

I own a m3D Rev.C myself.

I have several different revisions of the reference Videologic Apocalypse 3DX and two Matrox Rev. B. I've read that the Rev. A is supposed to be easier to overclock but this may be anectdotal.

Hi,
How did you OC a Rev. B card ? On the website you provided in the initial post it's said to be tricky with no procedure provided. I didn't find anything about OCing this revision.
Thanks.

Reply 31 of 47, by Grem Five

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Kahenraz wrote on 2021-09-24, 06:51:

I've thought about heat pipes soldered to a thin piece of copper but this is more mechanical engineering than I know. Don't you need a small torch to bend heat pipes without damaging them?

A cheap tubing bender is all one should need for bending but a small torch would be needed to solder the pipes just as plumbers sweat copper plumbing. They could be mechanical fitted with hardware but less efficient heat transfer.

GamersNexus How Copper Heatpipes Are Made

Reply 32 of 47, by Kahenraz

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JustJulião wrote on 2022-02-06, 02:35:

How did you OC a Rev. B card ? On the website you provided in the initial post it's said to be tricky with no procedure provided. I didn't find anything about OCing this revision.
Thanks.

I didn't. I've only overclocked the VideoLogic boards with replaceable crystals.

Reply 33 of 47, by JustJulião

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Kahenraz wrote on 2022-02-06, 05:53:
JustJulião wrote on 2022-02-06, 02:35:

How did you OC a Rev. B card ? On the website you provided in the initial post it's said to be tricky with no procedure provided. I didn't find anything about OCing this revision.
Thanks.

I didn't. I've only overclocked the VideoLogic boards with replaceable crystals.

Thanks for the reply.
I'll focus on my Videologic card then.
Have you finally mounted the Lattepanda heatsink ? Printed the Videologic Logo ? Would be curious to see it.

Reply 34 of 47, by Kahenraz

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It's been some time but I decided to finally revisit this. I ordered some adorably tony heatsinks from AliExpress that fit perfectly on the PCX2. I also added a pin header to steal 5v for the fan by soldering directly onto some pads. I applied some hot glue afterwards for some added strength, since this kind of joint is very vulnerable to mechanical stress. I tried to cut away some of the excess material so that it wouldn't look terrible, and I think it came out alright.

I made some observations by playing a bit of Tomb Raider at different resolutions, while swapping around various crystals between 66 and 80 Mhz. There appears to be some kind of frame rate smoothing or cap in this game, since the frame rate always wants to hug 60, 30, and 20 FPS, even at different resolutions. Although this game isn't a good source of frame data, anecdotaly, after swapping the crystal back and fourth, the difference was very clear. Even in the very first room of Tomb Raider, the game went from slightly choppy to extremely smooth. This game seemed pretty borderline at 1024x768 with the 66 Mhz crystal, but was able to easily benefit from even the modest bump to 80 Mhz.

In this test, I found the PCX2 GPU to be stable at 75 and 80 Mhz with no glitches or freezes. I still have more tests to perform and will share more data when I do.

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Last edited by Kahenraz on 2022-03-18, 08:10. Edited 17 times in total.

Reply 36 of 47, by Kahenraz

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Tested working at up to 90 Mhz. This larger heatsink keeps the chip quote cool.

I haven't heard anyone overclocking a PCX2 this high. It works great.

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Reply 38 of 47, by Kahenraz

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I've only tested Tomb Raider so far. I can see the FPS is higher, but the engine has a feature where it snaps to numbers like 20, 30, and then 60, so it's not granular enough for a comparison. It does raise the minimum and the experience is much smoother.

I'll have to find something else for a proper comparison.