You should put the socket of your motherboard in the thread title when asking for heatsink recommendations. In your case I'm guessing that would be socket 7.

Holy SH** you are right...i spaced on that one...yes, its a Super Socket 7 board......

If you want to go hardcore you can use socket 370, and possibly socket 462 coolers, as long as you have space (obviously). Or just stick with the generic aluminum coolers. My P233 builds all had nothing-special, generic aluminum coolers.

Thanks, was hoping there was something out there that really sticks out like you see with some newer coolers / heatsinks. I know the Socket 7 coolers are much smaller, but wasnt sure if something flashy or colorful was around....

If you want something colorful you can always replace the stock fan with one with LEDs on it.
As for the heatsink itself, P233 doesn't generate a lot of heat so a cooler designed for K6-2 or a modest S370 cooler will do the job.

Anyone have a good recommendation for a great passive cooler that could handle even a K6-III+ ?

tpowell.ca wrote:

Anyone have a good recommendation for a great passive cooler that could handle even a K6-III+ ?

Are you overclocking? If not, is your board able to supply lower voltages such as 1.6v or 1.7v? If yes, you can try and see if your CPU can work at such low voltages. In this scenario a decent S370 heatsink with good air circulation will suffice.
If you have to run the CPU at stock frequency at 2.0v or above, the next question is: is your board vertically or horizontally mounted? The socket and the board in that era ain't designed to hold heavy beefy heatsinks. They will eventually warp or even break after long time use. If your board is horizontally mounted, you can use copper S462 heatsink that fits your board and strengthen the socket with supports underneath the board. I used this heatsink for my horizontal K6-3+ build. I came across it on ebay but unfortunately I don't know its model.

In other cases, you might have to stick with air cooling or upgrade to water cooling.

There are copper Socket 7 heatsinks around that are pretty cool. I know startech made a couple, not sure about any other brands off the top of my head. Example here: https://www.newegg.com/Product/Product.aspx?I … N82E16835230034 and here is another good one here: https://www.newegg.com/Product/Product.aspx?I … N82E16835230015

The thinner the cooling fins the better. Those larger heatsinks that have the super thick fins are absolute trash in terms of cooling performance.

This specific Antec cooler works well.
https://www.ebay.com/itm/Antec-Solution-Plus- … r-/272846399589

ODwilly wrote:

There are copper Socket 7 heatsinks around that are pretty cool. I know startech made a couple, not sure about any other brands off the top of my head. Example here: https://www.newegg.com/Product/Product.aspx?I … N82E16835230034 and here is another good one here: https://www.newegg.com/Product/Product.aspx?I … N82E16835230015

I am not sure if you are replying to the OP or tpowell.ca. I have the first startech fan and it's really good at keeping the CPU cool, but its stock fan is way too loud and an overkill for P233. For P233 I would suggest replacing the fan with a quieter one. Its heatsink is a little too small for passively cooling a K6-3+ 450MHz at 2.0v. It fits on ASUS P5A-B whose lowest voltage setting is 2.0v, but it won't fit on GA-5SMM that can give me lower voltages.

ODwilly wrote:

There are copper Socket 7 heatsinks around that are pretty cool. I know startech made a couple, not sure about any other brands off the top of my head. Example here: https://www.newegg.com/Product/Product.aspx?I … N82E16835230034 and here is another good one here: https://www.newegg.com/Product/Product.aspx?I … N82E16835230015

I don't know about the copper one, but the 2nd item linked (the StarTech FAN370Pro) is the same HSF that I use.
I bought it a long time ago to fix heat problems with a K6-3 450MHz.
Recently I was running the same K6-3 with this heatsink at 2.3V. IIRC it was generally in the mid-40s, maybe 50C max.
I've used the same heatsink with a Pentium MMX at 250MHz, a Cyrix 6x86, a K6-2 500MHz, and even a Coppermine P3 933MHz. Don't remember the temps but none of these were any problem.
So basically it's performance is plenty good for anything on socket-7.
Currently it has a K6-3+ running at 1.8v, and even at 550MHz it's just cold. I have trouble getting it into the 30s, so I doubt it ever breaks 35C (but I can only check it after rebooting to the BIOS).
I temporarily ran it 600MHz at 2.05v and that was no problem either in terms of temperature (not stable but it wasn't getting hot).

I like that this heatsink uses a 60x20mm fan, which is bigger than a lot of socket-7 heatsinks use. The clip still makes me nervous to operate, but every socket-7 clip always has.

cyclone3d wrote:

The thinner the cooling fins the better. Those larger heatsinks that have the super thick fins are absolute trash in terms of cooling performance.

Thin and tightly spaced fins will perform better when clean, but they get clogged with dust more easily. Coarser fins maintain an even level of performance over a longer period of time.
IMO the coarser fins are a good tradeoff since even the hottest Socket-7 CPUs don't need enough cooling to make higher maintenance heatsinks necessary.

Sorry, I have never actually purchased a HSF for Socket 7 or 370. I have scrapped so many pc's that the stock HSF's relevant to the black HSF's remind me of the Celeron 370 ones and those are AMAZING for socket 7 from Pentium one to overclocked K6-2/3's. I ran a 233mmx on a stock passive, thick and massive Pentium 75 heatsink at one time, simply because of an amazingly good exhaust fan on that system.

I use StarTech's Socket 7 cooler for my K6-2/400, and it works like a charm.

I second the recommendation for the Startech Socket 7 heatsink. I have one in my triple purpose Pentium MMX 233 machine, and it has never let me down.

shamino wrote:

cyclone3d wrote:

The thinner the cooling fins the better. Those larger heatsinks that have the super thick fins are absolute trash in terms of cooling performance.

Thin and tightly spaced fins will perform better when clean, but they get clogged with dust more easily. Coarser fins maintain an even level of performance over a longer period of time.
IMO the coarser fins are a good tradeoff since even the hottest Socket-7 CPUs don't need enough cooling to make higher maintenance heatsinks necessary.

Tell that to the K6-2 550 I was running at 660 back in the day. The heatsink I was using got really, really hot. It was one of the larger socket 7 heatsinks that was available at the time. It was all aluminum, but was a taller one with not super thick fins. And I had stuck the highest output fan I could find on it.

All those other crazy heavy heatsinks of the time for Slot-A (Alpha P7125 with dual 60mm screamer fans - as seen here: http://www.dansdata.com/athlon.htm) and the supposed top dog for socket A before heatpipe coolers were available, the Swiftech MCX462 as seen here: http://www.frostytech.com/articleview.cfm?articleID=876 were really all trash compared to simple thin-fin heatsinks and magnitudes worse than heatpipe coolers.

I owned both the Alpha P7125 and the swiftech MCX462. They soaked up heat pretty well, but dissipated heat really poorly.

At stock speeds and voltages, the thicker-finned heatsinks performed ok-ish.. but still not cool enough for my tastes.

Thanks, I ordered the Startech Socket 7 heatsink....

Appreciate the help!