ATI + physx psu advice

[Enmity]

My current specs are in my sig and my power supply is a Silverstone Strider 750W.

Basically i've been thinking about upgrading from xfire 4850's to xfire 5850's. I'd like to gain the extra performance as the 512mb on these cards has become a bottleneck. I'm also thinking i'd like to play with physx while using ATI for rendering...something about that just seems fun.

From the research I have done i've found that 5850's consume slightly less power than my 4850's..so thats all good. Now, ive got a spare 8800gts 320mb and also a 9600gt which im thinking I can use as a dedicated physx card/ or sell along with the 4850's.

I guess the questions I have for you are :

Would xfire 5850s be worth it for my system, at 3.75Ghz would the Phenom be that much of a bottleneck?

would my psu have enough grunt to power 2 5850's plus either of the two nvidia cards mentioned above?...and if not...what is the least power hungry nvidia card I could purchase to run physx? eg: 85/94/9500gt's

I know a lot of you may want to say I should just upgrade my psu and then not have to worry about this sorta shit. The problem is I've just recently upgraded to a new case, finally have some great airflow and have all of my cables tied down. It'd be a mother of a job to re-wire everything all over again.

Thoughts? Any advice is much appreciated.

[[Ion]]

You will be very impressed with the Xfire 5850s, your Phenom might be a bit of a bottleneck but the gains will still be huge. Please note that in the latest drivers, Nvidia disables PhysX if there is an ATi card present in the system. However, if you are prepared to use older drivers, use the 9600GT for PhysX because it is just as fast, and more energy effecient (but your power supply could easily power either 3rd card). If needed you can use a Molex-PCIE power adapter to power the 9600GT

[wolf]

no need for a new PSU imo, two 5850's and a 9600GT would be a sick gfx + physx setup for some time to come.

[r9]

XFIRE and SLI are mostly for high resolution. That is where are most efficient. But knowing how great HD58X0 handle high resolutions. One HD5850 bios modded for higher voltage at 1000MHz Core would be plenty for me. I guess two would be better.

[Enmity]

thankyou for your prompt responses. another factor will be that I'll most likely have to drop down to pcie 8x rather than 16x to fit the 9600gt in lol..however in the benches ive seen this doesn't seem to effect performance in a huge margin to gain physx support.

Ion - in regard to the latest nvidia driver - is that even when using the physx hack which was recently released? It's been linked on tpu for maybe a week?...or has nvidia done the sly (again) since then and worked around the hack?

[Enmity]

alright i just checked it out, im currently using the top and bottom pcie slots running in 16x. Both the nvidia cards i have are both dual slot coolers so theres no way i could fit one in, also, it'd have to be significantly shorter than the 4850's because im using the 4x sata connections which are in a hideous place....hmmm...so really if this physx things going to work i may have to do a bit more research and find a short, skinny single slot card to use for physx lol...

ive attached a pic of the current setup to show you what i mean about the satas...what a bitch of a spot huh?

[fullinfusion]

I read a post from Mussles on this subject, he was saying the cpu bottle neck's the gpu till ya hit 4.2GHz on the cpu....

[ShRoOmAlIsTiC]

use the 8800gts 320mb, those have more rop's then the 9600 and from what I read the higher the rop's the bettter for physx. also the 8800 had 320bit mem which is better too I think. I just came off a 4850x2 with a 8800gts 320mb and it was a hell of a combo. Now I got a single 5870 and gtx 260. Only reason I got off the 8800gts was because I needed something that had dxva support, it was also my tv card.

[Mussels]

Originally Posted by fullinfusion

I read a post from Mussles on this subject, he was saying the cpu bottle neck's the gpu till ya hit 4.2GHz on the cpu....

that was on intel, not sure what clocks would give relevant performance on his AMD system.


regardless of this, you cant run ATI cards + physx.

nvidia has blocked it, physX will NOT enable unless the primary video card in a system is an nvidia one - and yes, this even applies to the Ageia PCI cards now.

[Steevo]

Guessing since GTA4 uses 50-60CPU at 3.7Ghz for me I could add another 4850 and be fine with overhead losses and all. My 4850 I have pushed to 735Mhz with a pencil mod and just a BIOS unlock for higher GPU speed. Withthe second pencil mod I have hit 790 core but it was slightly unstable, and my volt meter was uncalibrated.

[Mussels]

Originally Posted by Steevo

Guessing since GTA4 uses 50-60CPU at 3.7Ghz for me I could add another 4850 and be fine with overhead losses and all.

CPU usage in task manager doesnt show the CPU being used to feed the video cards. that is transparent to the OS.


I tested mine, where overclocking my video cards had less than 1% performance gain til i passed 4.2Ghz (which wasnt completely stable anyway)

[Enmity]

in regard to the 8800 gts i wont be able to fit this card inbetween my xfire set up as it is too long and will be blocked by my sata connections.

Physx can be enabled when using ATI as the primary gpu - heres an article about it which was released just recently. Of coarse you have to be on win 7 and must apply this hack to make it work. perhaps not with any nvidia driver released from this point on...but as of a week ago it should work.

http://www.techpowerup.com/105329/Ha...U_Present.html

I am now exploring the options of using a shorter single slot design nvidia card instead, perhaps a 94/9500GT...or a 220? they should be short and slim enough I reckon.

[Enmity]

this is pretty much what i'll be looking for - its single slot, its not very long so will fit between my xfire cards....know of a more powerful card about this size? or will the 9500 suffice for physx?

http://www.playtech.co.nz/upload/200908121554524.jpg

[Hayder_Master]

i think there is not bottlenick with 3.7 , also i see your psu is enough