PC Compatibility Card - PM 4400 PCI slot 1 or 2

So I've got my PC Compatibility Card bits coming (RAM, VRAM, Display Cable) and I'm curious about the mounting instructions for the 4400: the 4400 technical manual says you can put it in any of the slots, whereas the retail PC card instructions say to install in the second (lower) slot, regardless of installing the serial adapter/card or not.

Here's my dilemma: with the Sonnet Crescendo L2 card installed (it's a bit taller than the cache card) the PC card's heatsink rests on the top of the Crescendo. Probably not a good idea.



Testing it in the first slot, it appears to clear just fine (I'm propping it up to where my future bracket will hold it...), and I'm merely wondering if there's concern about airflow not getting to the SMDs on the "back" of the card. In any case,



I should probably mount it higher to clear the Crescendo. Just curious if anyone has any hard-and-fast reasons why mounting it up top is a bad idea.
 

IMO - I think it should be fine - just keep eye on it for couple of days

Cheers

AP

If you are worried about heat, you can always put on fresh thermal paste for better heat dispersion, and even put a little strip of kapton tape to separate the board from the cache. 

Your project is making me want to dig out my PC PCI cards from storage to install in my 4400. Well if/when I ever find them that is!  8)

I'd keep it in the top slot unless you notice any quirks (unlikely) - the Crescendo will be making 95% of the heat, not the Pentium by any stretch and it's good to have some airflow around the G3.

Just bought some VRAM for my PC compatibility card - housing it in a Blue and White G3.

omidimo said:

Fresh thermal paste for better heat dispersion

Click to expand...

Is there a trick for removing the heatsink? Other than the one wire spring tension I don't see anything, but it won't come off.

I tried gentle prying and nothing. Too paranoid to apply more force :[

I mean, those not-riveted pieces don't seem tight at so around the mounting holes on the heatsink itself, so unless it's the old paste just being stubborn. In that case I should definitely replace it.

Maybe a contact cleaner or IPA soak? Oven?

Byrd said:

i'd keep it in the top slot unless you notice any quirks (unlikely) - the Crescendo will be making 95% of the heat, not the Pentium

Click to expand...

Gotcha. I was told the whole card itself produces quite a bit, but if that's not the case, I'll definitely put it up top. I thought about drilling some holes in the removable pci mount plate for the Comm2 Ethernet to help airflow right through the back.

I had a 21x21 heatsink for the Rage128 that I removed to accommodate the 100BT card. I'll put it back on as well.

Oddly, with the comm2 card back in some downloads were displaying over 100base speeds ¯\_(ツ)_/¯ but at any rate my premium speed net will be disappearing end of month. Plua I couldn't get the farralon to work on 7.6.1 anyway.

And while airflow is on the docket, I have been noticing a fatal flaw in my PSU modification/upgrade—the ruddy fan pulls and pushes out, like most power supplies, but in the specific Dell I pulled, it pulls from the TOP... But the case metal sits practically flush and that fan just doesnt run as fast as a case fan does. Top of the case right there gets warm, but not really hot. However I should probably mitigate that beforr it becomes a real issue...

jessenator said:

it won't come off.

Click to expand...

The thermal paste has completely dried up, you can gently rotate the heatsink left and right to loosen, but don't pull. Once It is off, then you can clean it up and apply some new paste.

I have thought about reapplying paste to my Sonnet CPU upgrades lately as two decades later, they are probably not very effective anymore.

omidimo said:

gently rotate the heatsink left and right to loosen

Click to expand...

I give that a try. It's got those posts that look like botched rivets to hold it in place, so hopefully there's enough play I can work that off.

plot twist: it's NOT thermal paste!

It was some metallic tape... gross all the same



Explains why it was so difficult to extricate. I ended up using a nylon pry tool to twist it under the lip of the heatsink,




minor scuffs on the heatsink itself from initially attempting to lift up the tape with a stainless ruler. Not sure if that heatsink is painted or anodized. Either way, wouldn't that inhibit thermal conduction?

Yep thats a thermal PAD - you can buy those and stick it on - they come in 0.5mm and 1.0mm. Better than using thermal paste due thickness.
Cheers

AP

Mid 90s Apple was all over the map when it comes to heat management, so it is not surprising they went with a thermal pad. 

This pad has been on my amazon shopping list for a while. If you do use a pad again, let us know what you used. 

Haha, I was thinking about that exact graphite pad!

I do have a large tube of Arctic Silver I haven't opened... I do know it'll be much messier.

Maybe I'll see what the Crescendo looks like and order a couple pads or a larger pad (if they make it...) to save on shipping.

This has me wondering. Was the heatsink on these more of a CYA measure than an actual thermal solution?

Did socket 7 chips really get that hot in the day? My buddy has a Pentium 133 underclocked to 75 and is, in his words, "practically cool to the touch."

Most original Pentiums came with a very small heatsink and fan; later MMX series needed a chunkier HSF generally, and AMD/Cyrix equivalents generally ran hotter.  I wouldn't slather the Pentium 100 in Arctic Silver - it's too big a die to cover and not needed (and conductive; in the day of Arctic Silver I'm sure it killed many components from incorrect application) - just use the generic white goop, once you've scaped off the tin foil pad and surrounding paste.

Byrd said:

it's too big a die to cover and not needed (and conductive; in the day of Arctic Silver I'm sure it killed many components from incorrect application)

Click to expand...

Bingo! Most people apply way too much and forget the conductive nature. 

Looking forward to the naked Sonnet pictures now.

Byrd said:

Most original Pentiums came with a very small heatsink and fan; later MMX series needed a chunkier HSF generally, and AMD/Cyrix equivalents generally ran hotter.  I wouldn't slather the Pentium 100 in Arctic Silver - it's too big a die to cover and not needed (and conductive; in the day of Arctic Silver I'm sure it killed many components from incorrect application) - just use the generic white goop, once you've scaped off the tin foil pad and surrounding paste.

Click to expand...

So you'd recommend the white goopy paste over a graphite pad?

Basic goop would do the basic trick. Its cheap and functional. Worst case, if you think its too hot, just use something else. 

I use the premium stuff on my modern Macs (just re-did some 2012 minis), so I have Kyronaut to spare. I have yet to get a graphite pads. 

I actually looked at it last night, it's Arctic MX-4 still in the package, which is carbon based and non-conductive. I bought it last year and promptly forgot about it (cheap ebay impulse buy) when I built my Ryzen rig and replaced the annoyingly rev-happy wraithmax with a Dark Rock Pro 4, not knowing the Dark Rock came with Silver paste.

And as far as portioning, I never use more than a pea-sized dot for standard heat-spreaders. I'll probably do the pre-spread approach with the pentium.

I had a close-up look before I disassemble the Crescendo, and it looks to be a white thermal pad. But looking at a couple of nekked G3 ZIF modules there's more of like a frame of thermal pad around the whole of the chip and paste right over the much smaller die surface:


I'd like to emulate what was going on with the crescendo, so I'll probably end up getting an Arctic thermal pad and carefully trim it to the correct dimensions for the G3, a wee bit of MX-4, and then a nice even cut for the pentium—no paste.

And as cool as those IC Graphite pads are, they're also conductive, and there's less potential damage to a slab of silicone than a carefully manufactured graphite pad.

jessenator said:

I had a close-up look before I disassemble the Crescendo, and it looks to be a white thermal pad. But looking at a couple of nekked G3 ZIF modules there's more of like a frame of thermal pad around the whole of the chip and paste right over the much smaller die surface:

Click to expand...

That pad is to protect the exposed die from uneven pressure in case of improper heatsink installation, not for any thermal management. It's not strictly necessary unless you're klutzy or careless. 

Id put the PC Compatibility Card in the top slot, then get the 4MB VRAM card for the onboard video and the internal GIMO cable. I would also get one of the clone Tanzania 3-slot PCI cards instead of the stock 2 PCI/1 CS card. 

Franklinstein said:

I would also get one of the clone Tanzania 3-slot PCI cards instead of the stock 2 PCI/1 CS card. 

Click to expand...

I have been looking for those, and cant seem to find any. Found 5 slot-ers, but not 3 slot-ers.