Thought I would post an update to this. I am traveling at the moment so I don't have direct access to the machine so some of my numbers are just from memory. Got my $100CDN Sapphire 4870 512MB and installed it in my server (Q6600 @ 400X8, Biostar Tpower P45, OCZ Vendetta2, 2x1GB OCZ 800MHz, Ultra LSP 750W, Vista 32bit). I did a complete uninstall of the existing Nvidia drivers (had a Palit 8800GT Sonic 1GB). Installed the latest Cat 9.6 generic drivers from ATI's site. Stock clocks are the 750 core 900 memory from reference designs. The board is the blue PCB from Sapphire so I'm not sure if this is a non-reference design or just a change in the color? I did some searching and there were vague references to Sapphire using a 4 stage power rather than 3 stage on reference design? Can anyone confirm?
First impressions...
I like the ATI CCC interface. Straightforward and intuitive to use.
Folding is pretty poor compared to my Nvidia cards. The 4870 was getting about 2500ppd. My 8800GT would break 4000ppd. The GTX260 routinely gets 7000-8000ppd. Even my Q6600 SMP folding gets 2000-3000ppd depending on the WU.
The fan profile is really annoying. Even when just working on the desktop the fan would alternate between 2 settings (can't remember the exact numbers but they were around the 20% range IIRC). Just a few hundred RPM difference but spaced about 10 seconds apart I found it really irritating to hear the fan speed up, slow down, speed up, slow down.... Not loud. Just constantly changing pitch. Maybe I'm just sensitive to noise. Idle temps seemed to be in the high 40's C. Load (using ATI Tool spinning furball) was in the high 60's C.
First thing I did was set the fan to manual so I didn't get the constant variations in RPM. I found 30% OK. Louder than other fans in my system all set to midrange speeds on my fan controller (120mm inlet, 120mm exhaust, 80mm side panel, 135mm on power). Not irritating, just noticeable. Idle temps didn't change much but load would was now in the low 60's C. I do like that it exhausts the air out of the machine.
Ran some benchmarks (3DMark06, 3DMark Vantage, Crysis, Furmark). Much faster than the 8800GT (OC to 700MHz core, 1800 shaders, 2000 memory) that it replaced but not as fast as my overclocked GTX260 192SP (783 core, 1566 shaders, 2500 memory). The GTX260 is installed in pretty much an identical system except it is an ASUS P5Q-Pro... but still a P45 chipset. I set the clock on my Q6600 to the same 400X8 to keep things equivalent.
Next I tried some overclocking. It would pass the ATI Tool artifacting test @ 800 core / 1000 memory. That improved the benches a fair bit but still not up to the OC GTX260. For example, in Crysis bench it would get to within about 2 or 3 fps depending on the resolution.
I have an Accelero Twin Turbo on order (should have it tomorrow) to replace the stock cooler and lower the noise I hope. But in advance of that I decided to see how the card could do with better cooling. So I plugged my ears and set the fan to 100%. I have heard the comments about "leaf blower" and that's about right... Not unbearable but certainly wouldn't want to listen to that 24/7. But it did mean that my load temps were just peaking at about 50C under full load.
So with the leaves blowing out the back of my machine I started sliding the bars up in CCC. The BIOS in the card seems to allow 900MHz core max and I'm not sure about memory (something like 1200 I think). At 850 core I noticed artifacting in ATItool after about 10 seconds so I backed it off to 840MHz and that seemed to get me at least a few minutes artifact free (quick and dirty so I didn't wait too long). Then I started bumping the memory and 1100MHz seemed to work but got some artifacts after a minute or so. So I dropped memory to 1075 and that seemed to fix that.
So I ended up with 840MHz core and 1075MHz memory (4300 GDDR5). I benched that for a bit and it was obviously better but still didn't catch my GTX260 in my benches. I also noted some video anomolies (diagonal bars randomly across the screen) in the Crysis bench after about 15 minutes so the 840 core may be a tad too high. I may end up at 830MHz core.
From what I have read, 830 core and 1075 memory would be about average for OC on stock cooler. Maybe I can do a little better with the Accelero cooler but I'm not sure how the 4870 reacts to lower temps. For example, when I watercooled my GTX260 and dropped temps from the 60's to the 40's I only gained about one more notch in the core/shader increments (went from 756 core 1512 shaders to 783 core 1566 shaders). So the GTX260 was not really temp limited from my experience.
Next step is to look into bios volt-mod for the 4870. Not sure if this will work or not. Need to play with the RBE tool and find the voltage measuring points for my multimeter.
So that's pretty much the update. Will try playing with it some more once the Accelero Twin Turbo goes on there. Hopefully that cooling solution still allows another card in the second PCIe slot since I may try some crossfire later on.