I downloaded and installed The Witcher 2 today. I am well aware that my system is old but I thought I would be able to play with decent performance at the very lowest settings. When I say decent performance I mean 30+ fps.

My specs are

Opteron 175 @ 2.8Ghz
4Gb of ram
GTS 250 512Mb
24" monitor 1920x1200 res

I meet the minimum system requirements. I am not expecting to play this with any eye candy. I just don't want it to be a slide show.

I fired the game up and started it on low settings. It was jerky but playable.
I have spent a lot of time today trying to understand what the settings do, I've read the readme and so I have a fair idea of what to tinker.

I am finding that the game is very CPU intensive. When I run on low settings, my max fps is 21 fps at my native res. If I drop the res down to 1280x720 and run it in a window my max FPS is 30 indoors, 23 outdoors.
Even at 1280x1024 and running it on all low settings, my CPU is max 100% usage. My GPU though is at 63%.

Because of this I am able to crank up settings like shadows, lights, SSAO, blur effects and such and run the game at native res. My game still hovers around 20 fps, except now my GPU is at 96% load.

I am finding that the two major settings which affect me are Texture downscaling and dangled item limiter. If I don't enable those settings, and choosing low for texture downscaling is sufficient, I get 10-13 FPS, regardless of other settings and resolution.

So this all points to a CPU bound problem, I think this is where the game needs to be optimised more, unless the minimum system requirements was just false.

nope its gpu bound.

hardly scratches my quad-core

my GPU need a upgrade due to this.

thats why minimum requirements on the GPU is so high.

this game is also future-proofed.

I'm running an i5 750 and a GTX460 at high settings, 1920x1080. I tested running the CPU at the stock 2.6GHz CPU and 1333MHz ram as well as overclocking to 3.8GHz CPU and 1520MHz ram and it didn't make any noticable difference in the framerate.

It should be rather obvious that it is going to be bound by everything in general, and by the most overtaxed subsystem in any particular instance.

If you for some bizarre reason built a machine with a Quadro Plex 7000, enough Xeons to put yourself in the contact list of an Intel exec, and then put only 1 gb of the slowest ram you could find plus a 5400 RPM IDE drive, you'd be see no performance c/o memory and disk constraints. Pair a crazy cryocooled multi-graphics-card setup with a Merom CPU and you'd see it CPU limited. And so forth.

The game is very CPU dependent. The minimum system specs advertised could prob not run the game at all, my Q9550@3.3ghz and GTX 280 only give me 20-30 fps no matter the settings. I finally had to hook up an old 720p monitor to get a playable framerate.

See the sticky thread, Im runing a nvidia GT 240 with good specs. I just reinstalled the nvidia driver (clean install) without installing any 3D Vision features.
Try that, it got me going.

there is a difference between bound and intensive

As the devs mentioned, the more cpu power you have including cores (they said six core is great if you have it) the better it will run. Of course having a good gpu will help as always. Right now it seems there are major issues fps wise with the latest nvidia whql cert drivers, but they just released a beta that should fix it IF you keep 3d vision off (which is a shame since this game looks glorious in 3D). Else you risk inconsistent and crappy framerates..

There are reports from various places that you shouldn't bother running this on a dual core machine.

Most reports I've seen of people getting good frame rates have been from machines with tri-core or quads.

I think I'll wait playing this until I buy my new AMD bulldozer system.

I tend to agree; 3-core and 4-core rigs seem to be doing a lot better. I have it going on High with a 3-core Phenom II and an 8800 GTS 512. I'd love to see what the Socket AM3+ CPUs will do with the game. I've got an empty case waiting for one.

Your Opteron 175 system has to be a bit long in the tooth, though: even though you've overclocked it, it is Socket 939 and DDR. Time spent accessing RAM counts toward CPU usage too.

I'm running a dual core (athlon II 250 and a 5770) and everything is smooth with large textures and no downscaling. No SSAO though. This game does not seem to be very demanding at all.

The game wasn't very demanding CPU wise until you reach Flotsam.
When I got to that area I would get a lot of freezing.
I have two monitors so I viewed my task manager processes while playing the game and noticed my cpu was runnning at near max and when the game would freeze and then run smooth again the CPU was throttling from 94-98% to 54-63%.
This indicates my CPU is not powerful enough and is bottlenecking even my old 8800gt OC.
Without a bottleneck I would be getting around 27fps in that area using high preset except for texture size on large, LOD distance on far and having motion blur + SSAO diasabled.

When out of Flotsam the game runs smoothly though,
I might just upgrade my old Athlon x2 5200+ to a Athlon II x3 CPU to hold me off before I build my new computer when Nvidia releases their new GPU design.

My friend is running it on Ultra with an E8500 core 2 duo dualie and a good video card, so I dont think that is true. (Once he took care of the Nvidia 3D vision problem, that is) The Opty in the OP is just pretty dated. I think thats an old socket 939.

It might be an AMD thing, theres supposedly an issue that is being hotfixed, although Im running a quad Phenom 2, and havnt noticed anything.

I dunno. My e5300 seems to be doing the job just fine. Going by the resource count, the game isn't very heavy on CPU power(using both cores but only to 93%), GPU power yes. My GTS450 works great in ultra minus ubersampling at 1980x1020. It also likes ram, lots and lots of ram.

There using Hovak engine to do physic which is cpu bound,this why it better with tri core and over.

I get abit lag when I run over dead bodies since it doing collision calculation,I have an E8400 OC to 3.6ghz.