Update: On July 21st, Nvidia released WHQL 190.38 drivers available at their driver downloads page.
(Below is an earlier post from July 17th on the Beta 190.38 drivers)
FYI on new Nvidia Beta 190.38 Drivers (released 7/16/2009)
I had a few readers (running bootcamp) ask about last night's FYI/Link to the new Nvidia Geforce/ION Beta 190.38 Drivers for windows. (This is a beta, not WHQL, so you'll get a warning about that during the install.) The release notes PDF (varies by OS) has a complete list of fixes/changes/improvements as well as some GPU specific, app/OS specific issues, info on PhysX update (I disable PhysX on this single card install) plus notes on CUDA 64-bit video encoding support and that all GPUs in SLI are now available for CUDA app use. I installed the Vista 64bit drivers on a 2009 Mac Pro 8-core (2.66) running Vista 64-bit Ultimate.
One of the new features (for 'select' Geforce 9 series and later GPUs) that caught my eye is a user adjustable (via Control Panel) Power Management control mode - "adaptive" (default/Nvidia 'recommended') and "prefer maximum performance", which you can set as a global or app/game specific (via profiles). The "max" setting lets you "maintain the card at its maximum performance level when 3D apps (DirectX or OpenGL) are running regardless of GPU usage". In Adaptive (default) mode, the card monitors GPU usage and switches between modes based on the "performance demands" of the application. (Their quote is "this allows the GPU to always use the minimum amount of power required to run a given application and can even allow older 3D games to run in lower power modes if the game does not require full 3D performance".)
The only benchmarks I ran of previous (WHQL) 186.18 vs 190.38 beta drivers were Doom III (1920x1200, HQ, 4xAA, 8xAF) HOC timedemo (no audio, avg of 3 runs) - 186.18 drivers scored 161 FPS, 190.38 scored 167 FPS and a CineBench R10 (64-bit) comparison - the 186 drivers on this machine had a CB GL score of 5503 and 190.38 scored 6626, although I've seen scores vary a lot (200-500+ points). (BTW - as I mentioned on a page here back in April, for some reason I had very low CB R10 GL scores on this install with the ATI 4870 - it scored under 2100 w/Vista 64 Home Premium and initally about 1100 after a Vista Ultimate upgrade (to support both CPUs) - w/ATI Catalyst 9.4 drivers at the time. Other similar system owners had CB R10 scores (they said) of appx 6600 - the same as I had under OS X. I had installed the April 2009 DirectX update and game/app performance otherwise was very good, but I won't rehash all that here.)
I also ran a few quick games/apps with the 190.38 beta drivers to make sure nothing was broken. I did notice that with the new beta drivers the 285 card seemed to ramp up GPU temperatures (and fan speeds) in games much quicker than I'd noticed before with older drivers. (Control Panel was set to the default "adaptive" power mgmt mode and I verified the COD4 profile was also set to 'adaptive'.) Using EVGA's "Precision" utility and a Logitech G15 LCD Keyboard (temps, clocks, etc. reported on the LCD) showed the card quickly ramped up to (reported) 87°C and 51% fan duty cycle within a few minutes in COD4 (1920x1200/HQ settings/4xFSAA). This is about 15°C higher than I had seen back in early June with the 185.85 drivers during a short (10-20 min) COD4 session. Even in COD4 Act I, first mission with no heavy firefights the GPU temp ramped up very quickly (1-2 min) to 86/87C. (I don't remember checking the mac 285 temps with the 186.18 install so I can't swear this is new to the betas - but a Dual GTX 285 SLI setup in a PC running 186 release drivers runs at 72C after 1/2 hour of DX10 gaming, about the same GPU temps as I saw on the Mac 285 with earlier drivers.) Of course after quitting the game it quickly cycles down to lower clocks/lower temperatures. (BTW - a recheck after installing the WHQL 190.38 release showed the same thing - quickly ramping up to (reported) 86-87°C GPU temps within a couple minutes of play even in less 'intense' early missions.) Granted that's really not a problem (and I've had some other cards hit over 90C at times) but I'd like it to run cooler and I'll be looking at replacing the stock HS/fan with an aftermarket one. I already have one in mind...
Another difference I noticed with the beta. With the previous (WHQL) 186.18 release on the 2009 Mac Pro w/Mac GTX285 card, Dxdiag (DirectX diagnostics) reported the 285 as having only 494MB vram. I wrote EVGA about that a couple weeks ago (as a FYI - not that I had any functional/performance complaints) and was told the next release would correct that. (DXdiag ran on an NForce 780i motherboard PC w/dual 285's (BB clearance BFG 285's at the '2 for 1' literally clearance price) didn't show that reduced vram size with the same 186.18 drivers in Vista 64bit HP.) Anyway, that is fixed in the new beta release - it now shows 4GB vram on the Mac Pro (which I assume means the nvidia 'TurboCache' system ram feature must be working - Nvidia says that Vista controls the allocation of system memory to the GPU for TurboCache functions and references this Microsoft doc on Graphics Memory Reporting through WDDM from feb 2007). BTW - I run the "Classic" desktop setting, not Aero.
At this point I'm not sure if I'll revert back to the 186.18 WHQL drivers on the Mac Pro. I'll decide that after spending more time with the beta, but have no plans to install the beta 190's on the 780i based PC w/dual 285s/SLI. It's not used that much anyway. If I were using CUDA apps however I'd be tempted to install the 190 drivers on that machine.
I (and many other owners) hope that eventually there will be a utility for OS X that allows user control of the Mac GTX 285's power saving modes/clocks. (As mentioned in my review and in many posts on the web, the power saving seems more aggressive in OS X. In other than really taxing 3D apps like Games, the card doesn't seem to always fully clock up. See review for notes on its variable GPU/shader/memory clocks.)
I welcome other reader (bootcamp/native install or VM users) feedback on the 190.38 Nvidia drivers. (include your mac model/OS/Nvidia GPU used.)