fastest gfx before my cpu is the bottleneck?

phillips321

Distinguished
Jan 17, 2008
4
0
18,510
Hi guys,

My current spec is as follows:
Pentium D 820 (2.8GHz dual core)
3 Gb RAM
2x160Gb HDDs
7900GS 512MB

I've lately been looking for a new gfx card as i've just recently got a new 1920x1200 monitor. I have been told that purchasing a 8800GS 512MB would be a bit of a waste of money as my cpu would be the bottle neck, what in theory would be the fastest card i could by where both the cpu and the gfx are the bottle necks?

I haven't got the money to shell out on a new mobo, cpu, mem and gfx so please don't advise i scrap the lot.

Are there any scales on the web that match gfx cards to equivalent cpu. This sort of scale could show the cpu+gfx couple that would best match to prevent either from being a huge bottle neck, i.e. it's obvious that pairing a 8800ultra with a celeronD would be a waste of time(money).

Anyone got any ideas?

Cheers guys

P.s. To re-summerise what's the fastest card i could have without my cpu becoming a serious bottleneck?
 

Acethechosenone

Distinguished
Jan 2, 2007
107
0
18,680
I thought high resolution was all about GPU! So I will keep quiet about the GPU issue and let a pro handle it.

Anyways since you have an LGA775 motherboard, check the manufacturer's website. Most of those boards support core2 duo with a simple bios upgrade.
 

phillips321

Distinguished
Jan 17, 2008
4
0
18,510
sadly my motherboard came as part of my packardbell pc.

Here is a link to the mobo http://support.packardbell.com/uk/item/index.php?i=spec_mexico&ppn=PB34230501.

There arn't any updates for this bios on this website but it looks like the motherboard is made by gigabyte. I have investigated further to see if it supports a core2duo but can't find anything. I guess the only way to know would be to buy a chip and test it, would be a huge waste of money if it didn't work :(

Know anyone in gloucester that'll allow me to perform this test using their chip?
 

makotech222

Distinguished
Mar 30, 2006
272
0
18,780
i have the same CPU as you, but with a 8600gts. i defintely hate my CPU. im getting a wolfdale system as soon as it comes out on newegg. It definitely feels like a bottleneck as it is.
 

homerdog

Distinguished
Apr 16, 2007
1,700
0
19,780
Download the trial version of Everest. It will tell you everthing you need to know about you motherboard. Sorry, I don't have time to link it right now, just use google.
 

rgeist554

Distinguished
Oct 15, 2007
1,879
0
19,790
I thought high resolution was all about GPU! So I will keep quiet about the GPU issue and let a pro handle it.
Sorta... let me explain it the best way I know how.

Ok, here's our example setup:

At 1280x1024 resolution, the GPU renders 120 FPS. The CPU can process only 60 FPS. Therefor 60 FPS are not displayed. In this situation, the CPU is obviously the bottleneck since it can't keep up with the GPU.

At 1920x1200 resolution, the GPU renders 50 FPS. The CPU can process 60 FPS. All frames are displayed, but your CPU could still process 10 more frames. Your GPU is the bottleneck here since it can't max out the CPU's potential.

In other words, if your CPU is the bottleneck, just up the res until you notice a decrease in frames.

As for your original question: Just get an 8800GT (if you're on a budget) or a GTS if you're not. The GTS is slightly better and performs pretty well, even in the 1920x1200 range. Afterwards, upgrade the CPU to a C2D. Something like an E8400 on a GA-P35-DS3L (may require a BIO update to work with 45 nm). That would be a great combo with the GPU.
 

yadge

Distinguished
Mar 26, 2007
443
0
18,790


Raising the resolution won't get rid of a processor bottleneck. The way I understand it, there is a cpu upper limit and a gpu upper limit. Say the processor can supply the frames to the gpu at 50 fps. Now, say the gpu can get you 50fps also, when playing at 1680 X 1050. So they are even.

When you raise the resolution to 1920 x 1200, the gpu can only give 30 fps. The cpu limit is still there, it is just higher than the cpu limit.

Now, say you set it at 1440x 900. And the gpu can get you 70 fps. Well, the limit on the cpu is still 50 fps. So that's all you get.

That's why they say the cpu is more important at lower resolutions. It becomes slower than the gpu, and becomes the bottleneck. But, that does not mean you can get rid of that bottleneck just by raising the res.

I hope that makes sense.

And... all the numbers were completely made up, of course.
 

rgeist554

Distinguished
Oct 15, 2007
1,879
0
19,790
So here's a question: what res would you have to run a 2600XT before a 1.7 ghz CPU became the bottleneck?
Not quite that simple.
Is it single, dual, or quad-core?
What architecture is it on?
How many IPC's?

To kind of give you a more dumbed down version. The lower the res, the more frames the GPU can render. The more frames... the harder it is for the CPU to keep up... see where this is going now? :p

 

phillips321

Distinguished
Jan 17, 2008
4
0
18,510
ahh that helps then, basically all the games i want to play run fine at 1280x1024 but when i try to run them at 1920x1200 i start to notice issues, i guess i'll be able to upgrade my gfx without noticing too much problems.

I have a look on the net and noticed that the fastest cpu my mobo can handle is a Pentium D 960
http://www.gigabyte.com.tw/Support/Motherboard/CPUSupport_Model.aspx?ProductID=1907

I can get one of these cpu's for around £120ish, are they any good?

Might start looking for an 8800gt card now, thanks guys
 

rgeist554

Distinguished
Oct 15, 2007
1,879
0
19,790
no dont bother. it wont provide hardly ANY difference in CPU power. step up to a core2 when u can.
Agreed. If you want a little more performance, just overclock a little bit to match the speeds of the 9xx, but don't spend any money on it. I can personally guarantee you that you wont be satisfied with that £120 purchase. :)
 

cleeve

Illustrious
Depends on the game. But in general, I think your 2.8 paired with that 7900 GS is optimal. You might get more out of an X1900 XT/7900GTX/8800 GS or the upcoming 9600 GT, but I think I'd stop short of a 2900 PRO, 3850, or 8800 GT on that CPU.