Cpu's and 'bottlenecking' graphics cards

[nreo]

howdy all,

im about to upgrade graphics card in a rig of:

amd x2 4200 @2.2ghz
2gig corsair ddr2 800mhz ram
xfx7900gtx
asus m2n-sli deluxe

Now graphics cards = gaming, thats how much i understand. The thing is, IS my cpu good enough? Lets say I got a 3870

Would games in a
amd x2 4200
2gig
3870

play as well as a rig of

intel quadcore 6600
2gig
3870 ?


I don't quite understand how much cpu matters!

Thanks

Chris

 

[SlowSpyder]

There really isn't a yes/no one size fits all answer. It depends on several things, the game you are playing, what settings you play at, what resolution your montior is, etc.

Your 4200+ will work fine with a 3870. But, with that being said there are times where you will not get all the frames per second you could due to that CPU. Depending on the factors above, there are times where your FPS is limited by the CPU, and there are times when your FPS is limited by your graphics card. There are games where going to the newest fastest overclocked quad core will have no/minimal impact on your FPS, and there will be other times/games where a newer faster CPU will give you a nice bump in game performance.

In my opinion imprtance of hardware ranks something like this: GPU>RAM>CPU You can have a pretty decent gaming experience with a high end graphics card, 2 gigs of memory, and a middle of the road CPU. Your gaming experience would suck with a super fast quad core, 2 gigs of memory, and a GeForce FX5200. And you wouldn't want to game on either system with 256MB of memory.

 

[myocardia]

Originally posted by: nreo
Would games in a
amd x2 4200
2gig
3870

play as well as a rig of

intel quadcore 6600
2gig
3870 ?

No, you'd definitely be CPU-bound right now, with a 3870. As a matter of fact, you're most likely CPU-bound right now, with your 7900GTX. Of course, the answer to your question depends on alot of things, like what games you're playing, at what resolution, and with how much AA. If you're playing @ 1920x1200, with 8x AA, you're GPU-bound in all games. But, if you're playing @ 1280x1024 with 2x AA, you're going to be CPU-bound in most games.

The way to tell if you're CPU-bound or GPU-bound is to see if your framerates increase by much, when you lower your resolution. If they don't, you're CPU-bound. If they do, you're GPU-bound.

 

[themisfit610]

I'm HEAVILY CPU bound in crysis with my 8800gt. My experience at all high 1920x1200 is very similar to my experience at 800x600 all low. That is to say, almost unplayable in heavy action.

So do yourself a favor and get a new CPU too. I'm leaning towards a 6400+ X2 Black. At 3.2 GHz they're screaming fast, and for $170 they're dirt cheap compared to a 3 Ghz C2D.

~MiSfit

 

[RussianSensation]

Like mentioned above, the answer is that it depends on the resolution, image quality settings and the games you play. But to illustrate take a look here:

Crysis CPU scaling

In this currently most demanding GPU game, at 1024x768 the difference between cpus is significant. However once you get to 1600x1200, it diminishes as the load on the graphics card is far more strenuous.

Generally speaking HD3870 will let you increase image quality a lot over 7900GTX for "free" so to speak. However, there is no cpu right now that will double your speed in games. Why? Because when you play games you crank all the image quality settings as high as possible which means majority of the time your gpu is on its knees (at least that's how I play). I can turn on softshadows in Chronicles of Riddick and my framerates will decrease by a factor of 2x on an 8800GTS!

Of course, it's still correct to say that 4200+ bottlenecks a 7900GTX because if you put in the fastest cpu in the world, you'll get an increase in framerates (especially minimum frames). However, what bottlenecks your system more is the more important question.

You can always make 7900GTX the bottleneck because the minute you turn 4AA at 1600x1200 in latest games your 7900GTX will come to a crawl, which makes the 7900GTX the real bottleneck here. You can put in a 10Ghz 8 core Nehalem in your system and it'll only increase your frames marginally at this point. If you play at 1280x1024, it might be smarter to get the 256mb 3850 and then in a year and a half you jump to Intel's new microarchitecture.

Of course there are exceptions like microsoft flight simulator where cpu speed matters a lot. The point is it really does depend on the resolution and the games you play.

You can check out Gamespot for various latest games you play and their performance cpu scaling guides.

 

[Spike]

Here is a way of looking at it from a different perspective.

If all you are looking for is an increase in gaming performance and you can only afford one upgrade then a vid card is your best bet. Yes, you will get better performance from a faster CPU + faster vid card but it's not like upgrading your card will hurt any.

If the price is right I am picking up an 8800GTS G92 to go with my rig below. Yes, it will be "cpu bound" but later on I'll build a new rig based around this GPU. Until then I get a huge boost in performance compared to my 7800GT.

 

[NickelPlate]

If you're CPU limited, then it means your graphics card is having to wait to draw a frame until the CPU performs some function/s. Usually things like calculating the AI of an enemy, object or doing some physics calculations.

NP

 

[nreo]

Thanks for the brilliant response guys. My computer hardware knowledge is ever, slowly, increasing .

In response to myocardia, I think you're right. I am cpu bound with my 7900gtx, as its a super card and i'm averaging not as good frames as i'd expect. But because of this cpu limitation, would i see a notable increase in fps with the 3870?

Now the game i'm playing here is call of duty 4. 1280x1024 and no AA is perfect for me. I'm just looking for as many frames per second I can get. I stuck my 7900gtx into my brothers pc, (a intel e6600) and he gets much more fps then my x2 4200.

So just the way im seeing it is:

7900 GTX = 125 fps = CPU BOUND

would I then have a CPU BOUND 3870 at maybe 150fps, those 25 extra frames down to the gpu, but the cpu then limiting the potential frames i could be achieving. Now this is just an example, not saying its exactly right, but am i on the right track?

Basically what i've gathered from this is that i need another cpu too to get the most out of my rig. Is a 6400 black edition good? Or a phenom 9500?

Thanks again

Chris

 

[Mr Fox]

Originally posted by: nreo
Thanks for the brilliant response guys. My computer hardware knowledge is ever, slowly, increasing .

In response to myocardia, I think you're right. I am cpu bound with my 7900gtx, as its a super card and i'm averaging not as good frames as i'd expect. But because of this cpu limitation, would i see a notable increase in fps with the 3870?

Now the game i'm playing here is call of duty 4. 1280x1024 and no AA is perfect for me. I'm just looking for as many frames per second I can get. I stuck my 7900gtx into my brothers pc, (a intel e6600) and he gets much more fps then my x2 4200.

So just the way im seeing it is:

7900 GTX = 125 fps = CPU BOUND

would I then have a CPU BOUND 3870 at maybe 150fps, those 25 extra frames down to the gpu, but the cpu then limiting the potential frames i could be achieving. Now this is just an example, not saying its exactly right, but am i on the right track?

Basically what i've gathered from this is that i need another cpu too to get the most out of my rig. Is a 6400 black edition good? Or a phenom 9500?

Thanks again

Chris

The thing that sadly missing from this conversation is the effect of Hard Drive Performance, and that if you cannot "Feed the Beast" you will lag....

Hard Drive sub systems are mostly ignored here, and they are a big part of the equation.

They are one of the most limiting factors of a modern computer.

 

[spittledip]

Originally posted by: Mr Fox

Originally posted by: nreo
Thanks for the brilliant response guys. My computer hardware knowledge is ever, slowly, increasing .

In response to myocardia, I think you're right. I am cpu bound with my 7900gtx, as its a super card and i'm averaging not as good frames as i'd expect. But because of this cpu limitation, would i see a notable increase in fps with the 3870?

Now the game i'm playing here is call of duty 4. 1280x1024 and no AA is perfect for me. I'm just looking for as many frames per second I can get. I stuck my 7900gtx into my brothers pc, (a intel e6600) and he gets much more fps then my x2 4200.

So just the way im seeing it is:

7900 GTX = 125 fps = CPU BOUND

would I then have a CPU BOUND 3870 at maybe 150fps, those 25 extra frames down to the gpu, but the cpu then limiting the potential frames i could be achieving. Now this is just an example, not saying its exactly right, but am i on the right track?

Basically what i've gathered from this is that i need another cpu too to get the most out of my rig. Is a 6400 black edition good? Or a phenom 9500?

Thanks again

Chris

The thing that sadly missing from this conversation is the effect of Hard Drive Performance, and that if you cannot "Feed the Beast" you will lag....

Hard Drive sub systems are mostly ignored here, and they are a big part of the equation.

They are one of the most limiting factors of a modern computer.

Speaking of which, did you see the review on those Solid State Drives? Once those become affordable and perform a little bit better, hard drives will be less of a limiting factor.

 

[Inspector Jihad]

a slightly OC'd x2 4200 wouldn't hold back a 3850, would it?

 

[nreo]

I would like to know that

 

[SlowSpyder]

Originally posted by: Inspector Jihad
a slightly OC'd x2 4200 wouldn't hold back a 3850, would it?

Same story as above... it'd probably do ok, but there would be instances where a faster CPU would equal better performance.

I run an Opteron 165, I used to have it overclocked to 2.7ghz. It no longer seems to be able to run at 2.7ghz for some reason, so now I am stuck at 1.8ghz, atleast until I can spend some time messing with it.

For the most part I don't notice much of a difference, but there are times where a game will sputter where it used to not sputter. I think the faster CPU would help me more with minimum frame rates. I just have to decide if I'd like to spend a few bucks on a faster s939 CPU (assuming I won't be able to get a decent oc back on my current CPU) or upgrade my platform all together.

 

[themisfit610]

well here's my perspective - if you're getting 125fps in a game, you need to turn your settings up!!

Anything over 60 is utterly pointless, since your monitor can't actually display any more than that.

If you're getting over 60, and you're at your LCD's native resolution, then jack up the visual settings and AF, or add a chunk of AA to your plate.

~MiSfit

 

[RussianSensation]

Originally posted by: Mr Fox

The thing that sadly missing from this conversation is the effect of Hard Drive Performance, and that if you cannot "Feed the Beast" you will lag....

Hard Drive sub systems are mostly ignored here, and they are a big part of the equation.

They are one of the most limiting factors of a modern computer.

Yes you are correct. However, the discussion focuses on gaming performance (i.e. frames per second). All modern hard drives are sufficient enough for providing fast enough IO performance during gameplay. The difference will be primary related to how fast the drive loads game/section levels rather than providing a boost in performance during gameplay.

themisfit610, also makes an excellent point. In fact at 120+ framerates, it is very important to turn on VSync because tearing and sudden fluctuations to even 60fps can make the experience more uncomfortable rather than a constant VSynced 60fps. Furthermore, the idea is to increase image quality settings as far as you can during gameplay but not so much as to reduce smoothness or your effectiveness in say aiming in FPS games. Some games are also more sensitive to framerates. Chronicles of Riddick VSync plays smooth as butter even when frames fluctuate from 30-60-30 back and forth during gameplay. However, try playing BMW M3 Challenge and the minute frames drop from 60 to 55, you feel it instantly

Considering Call of Duty 4 Benches, the game appears to be heavily GPU limited and prefers Nvidia cards.