MSI 580 Lightning

[Gautam]

Ok, so I tested some more GTX 580 with and without IHS. If you make good contact (Freeze or GC-Extreme thin layer, backplate and high pressure) and have a good card without IHS you can do ~1525MHz 3DMark03, ~1450MHz 3DMark11 and <1400MHz Heaven.
In the same condition but with IHS you gain ~125MHz in low intensity benchmarks (3DMark03, 3DMark01, 3DMark05, AQ3,etc) and more in high intensity ones (Vantage, 3DMark11, Unigine). The only card that have IHS is a Matrix that's a poor clocker on air and on LN2, but I managed to do 1520MHz 2k3 and 1375MHz Unigine easy...

The way to go is definately with IHS but I still don't understand why? The question is how do I mount now the IHS back on my very good Lightning?!

I have yet to test a 580 Lightning, but on the 480 Lightning, no IHS appeared to result in better core frequencies while the memory became pretty much un-overclockable. Actually did a test one step further with an IHS and a shim on top of the IHS, and I ended up getting stunningly high memory clocks, higher than 1400MHz, whilst normally the card would struggle to break past ~1220 on LN2. So, it appeared that the memory clocked worse the closer the pot was to the PCB. With the IHS off, not even 1200 was doable, with the IHS, a bit past 1200, and with a shim on top of the IHS, over 1400. It might not necessarily be the memory causing problems in the case of the 580 Lightning, but my guess would be that it's something on the PCB that's getting just a little too cold because the pot is closer to it when IHS-less. (yes, that 2mm is significant)

It might be worth a shot to pull out the hair dryers when going without the IHS. It's no secret that it helped the 480L.

[Splave]

started to lap in hopes of turning a good card to a great one lol epic fail IHS?

hopes this helps break into 1600's will know tomorrow

[matose]

started to lap in hopes of turning a good card to a great one lol epic fail IHS?

hopes this helps break into 1600's will know tomorrow

So the lapping helped or not ?

[SoF]

The issue is probably related to the cooling area, it's just too much heat for a pot to cool down in a too small of a space without the IHS.

That's something I specially see with singlestage and cascade lately. Cards with HS (benching 8800-series of all kind) will get much lower GPU core temperature compared to thoose without. Also getting the optimal mounting without heatspreader is a pita...I know the perfect target for cascade is ~-64°C idle but I usually only get ~-55°C idle and ~-9°C after longer load (03, 06)....tightening the screws during running - helps a bit but just in rare cases I am getting an even pressure on every edge of the core.

no IHS appeared to result in better core frequencies while the memory became pretty much un-overclockable. Actually did a test one step further with an IHS and a shim on top of the IHS, and I ended up getting stunningly high memory clocks, higher than 1400MHz, whilst normally the card would struggle to break past ~1220 on LN2. So, it appeared that the memory clocked worse the closer the pot was to the PCB. With the IHS off, not even 1200 was doable, with the IHS, a bit past 1200, and with a shim on top of the IHS, over 1400. It might not necessarily be the memory causing problems in the case of the 580 Lightning, but my guess would be that it's something on the PCB that's getting just a little too cold because the pot is closer to it when IHS-less. (yes, that 2mm is significant)

Same issues already appearing with G80/G92 - I have one 8800 GT here that won't do even stock mem clocks on cascade...the problem is very hard in 03 and 05 (GT2-GT3, funny fuzzy squares for 1-2 seconds and then freeze).
Depending on the card it does start with PCB temperatures below 10°C (A64 anyone?! ) - Try to keep the pcb warm, not using to much rubber (it strongly supports that effect!) and maybe even heat up the pcb are the only ways to overcome that issue...