How bad is a CPU 'bottleneck'?

The Seventh One · 25 May 2009 at 22:28

Hey all, I got the XFX 4890 recently and before I bought it I was aware of bottlenecks but couldn't really tell by how much. Been playing COD4 and in some places... fairly often in fact, my FPS drops to like 20, I didn't expect the bottle neck to be quite this severe.

I am playing with everything on max and at 1680 x 1050 to try put more stress on the card instead. My specs are as follows:

DFI LANPARTY UT SLI-D
AMD 4200+ X2 overclocked at 2.75GHz (Stock is 2.2GHz)
2 gig of RAM
XP SP2 (Fresh install just today), I also have access to Vista and Win7
Catalyst 9.5

It's an old rig I know but I had the 4890 as a bit of 'later on in the year proof' as thats when I plan on updating the rest of my system.

So in conclusion, is the bottleneck really that bad? and is there anything I can perhaps do to improve on the FPS with the current setup?

Thank you in advance

95thrifles · 25 May 2009 at 22:29

you might find a couple gig extra RAM may help, thats more likely to be bottleneck than CPU in your system, and its a cheap upgrade

D13 · 25 May 2009 at 22:32

In your case it is no suprise, the 4890 is a beastly performer and your cpu (for gaming) is very very dated, you have already overclocked so all you can do is upgrade

yeah, or as suggested more ram would help soz i missed that lol

Duran · 25 May 2009 at 23:20

bottlenecking is mostly an urban legend

no_1_dave · 25 May 2009 at 23:43

Makes a huge difference.
Athlon X2 is 5+ years old now, there are graphs to show bottlenecks, maybe worth googling.
If I remember correctly, a X2 with an 8800 performs roughly the same as a Core2Duo with a 6800/7900. Obviously thats only roughly, it was a while ago I read it.

IMO there is not point in having a 4890 with an X2, you could use a £50 8800GT & get the same performance. Your CPU is limiting you in a big way.

Orangey · 25 May 2009 at 23:45

Duran said:
bottlenecking is mostly an urban legend

OP, you will need a new CPU. But if you don't want to upgrade just yet then that's your decision.

95thrifles · 25 May 2009 at 23:46

Duran said:
bottlenecking is mostly an urban legend

no its not, a system can only go as fast as its slowest component, so whatever is slowest limits everything else
Whilst the CPU will be a limiting factor I do think you might see a nice boost with the extra 2gig of RAM, and as b4 its a very cheap upgrade option so worth testing

d3moliti0n · 25 May 2009 at 23:48

Sorry to kinda 'hijack' the thread as it were but I'm in a similar situation except I haven't upgraded my GPU yet. Would either my Pentium Dual-Core E2180 overclocked to 3GHz (stock speed is 2GHz, I'll probably try to OC it up to about 3.2GHz if I get a new PSU) or my 2GB of Corsair DDR2 memory bottleneck a GTX 260 (216)? I thought it would be better to ask here instead of start a brand new thread.

no_1_dave · 25 May 2009 at 23:52

d3moliti0n said:
Sorry to kinda 'hijack' the thread as it were but I'm in a similar situation except I haven't upgraded my GPU yet. Would either my Pentium Dual-Core E2180 overclocked to 3GHz (stock speed is 2GHz, I'll probably try to OC it up to about 3.2GHz if I get a new PSU) or my 2GB of Corsair DDR2 memory bottleneck a GTX 260 (216)? I thought it would be better to ask here instead of start a brand new thread.

2Gb will bottleneck you
The CPU will be fine for most games, only games that use multicore like GTA 4 will be limited.
Max settings for a lot of modern games require over 3Gb ram. The higher the settings you play at, the more ram you need. Using a 260 I assume you will want to be able to use high settings!

Orangey · 25 May 2009 at 23:53

d3moliti0n said:
Sorry to kinda 'hijack' the thread as it were but I'm in a similar situation except I haven't upgraded my GPU yet. Would either my Pentium Dual-Core E2180 overclocked to 3GHz (stock speed is 2GHz, I'll probably try to OC it up to about 3.2GHz if I get a new PSU) or my 2GB of Corsair DDR2 memory bottleneck a GTX 260 (216)? I thought it would be better to ask here instead of start a brand new thread.

I have one of those CPUs knocking around and yes, I'm afraid it will. The 260-216 is another beastly GPU that needs pairing with a 3GHz+ Core2 with plenty of L2 cache (the E2180 only has 1MB, the 65nm ones 4MB and 45nm ones have 6MB).

J.D · 25 May 2009 at 23:53

The Seventh One said:
Hey all, I got the XFX 4890 recently and before I bought it I was aware of bottlenecks but couldn't really tell by how much. Been playing COD4 and in some places... fairly often in fact, my FPS drops to like 20, I didn't expect the bottle neck to be quite this severe.

I am playing with everything on max and at 1680 x 1050 to try put more stress on the card instead. My specs are as follows:

DFI LANPARTY UT SLI-D
AMD 4200+ X2 overclocked at 2.75GHz (Stock is 2.2GHz)
2 gig of RAM
XP SP2 (Fresh install just today), I also have access to Vista and Win7
Catalyst 9.5

It's an old rig I know but I had the 4890 as a bit of 'later on in the year proof' as thats when I plan on updating the rest of my system.

So in conclusion, is the bottleneck really that bad? and is there anything I can perhaps do to improve on the FPS with the current setup?

Thank you in advance

I have the 4870 and E2180 @ 3.2ghz and my frames are fine. This is both at 1600x1200 and 1920x1440 which I run. I ran at 1600x1200 before due to my 8800GTX and ran this for a day on the 4870. Since changing up a resolution I don't drop FPS to a noticeable level unless it's heavy with smoke. I disable "field of view" for multiplayer.

d3moliti0n said:
Sorry to kinda 'hijack' the thread as it were but I'm in a similar situation except I haven't upgraded my GPU yet. Would either my Pentium Dual-Core E2180 overclocked to 3GHz (stock speed is 2GHz, I'll probably try to OC it up to about 3.2GHz if I get a new PSU) or my 2GB of Corsair DDR2 memory bottleneck a GTX 260 (216)? I thought it would be better to ask here instead of start a brand new thread.

I don't think so but first I'll need to know what your max resolution is?.

Duran · 25 May 2009 at 23:54

95thrifles said:
no its not, a system can only go as fast as its slowest component, so whatever is slowest limits everything else
Whilst the CPU will be a limiting factor I do think you might see a nice boost with the extra 2gig of RAM, and as b4 its a very cheap upgrade option so worth testing

what i meant is that people overreact about it. of course a pentium 4 will bottleneck a modern graphics card for example.

J.D · 25 May 2009 at 23:55

Orangey said:
I have one of those CPUs knocking around and yes, I'm afraid it will. The 260-216 is another beastly GPU that needs pairing with a 3GHz+ Core2 with plenty of L2 cache (the E2180 only has 1MB, the 65nm ones 4MB and 45nm ones have 6MB).

It's dependant of resolution. If a different CPU would gain you a few FPS at 1680x1050 but both games are playable then that is showing a slight bottleneck but not at the expense of the gamer on either CPU.

d3moliti0n · 25 May 2009 at 23:55

J.D said:
I don't think so but first I'll need to know what your max resolution is?.

The maximum resolution I use is 1680 x 1050 on a 19" LG LCD monitor, and I won't be upgrading that any time soon as the monitor is rather new.

J.D · 26 May 2009 at 00:38

d3moliti0n said:
The maximum resolution I use is 1680 x 1050 on a 19" LG LCD monitor, and I won't be upgrading that any time soon as the monitor is rather new.

You'll see a slight bottleneck but I greatly doubt that it will impact enough to make it unplayable on a 3.2ghz Dual core Intel vs 3.6ghz-4ghz Intel. In all honestly.

Mattus · 26 May 2009 at 03:38

The E2180 should cope fine with the GTX260. Will clearly be noticeably slower than a chip with more L2 cache/FSB, but it will be an incremental difference rather than holding you back in a big way.

The X2 4200, on the other hand, will seriously hinder frame rate on modern games. The low minimum FPS is a classic symptom.

thegoonden · 26 May 2009 at 07:35

Duran said:
bottlenecking is mostly an urban legend

True for Furmark and Crysis maybe, but with many many other 3d applications you will find that a 5% overclock on the CPU makes a VAST difference compared to a 20% overclock on the GPU.

The idea that every single thing will be held back by the CPU IS a legend, but so is the idea that it never happens.

To tell if you're being bottlenecked it's just a matter of slowing the CPU and GPU down (or if you have the headroom, overclocking them) in turn. Whichever one makes the most difference is the one holding the system back for that particular program.

Rezident · 26 May 2009 at 09:03

J.D said:
I have the 4870 and E2180 @ 3.2ghz and my frames are fine. This is both at 1600x1200 and 1920x1440 which I run. I ran at 1600x1200 before due to my 8800GTX and ran this for a day on the 4870. Since changing up a resolution I don't drop FPS to a noticeable level unless it's heavy with smoke. I disable "field of view" for multiplayer.

I don't think so but first I'll need to know what your max resolution is?.

About how much faster did you find the 4870 over the 8800?

TheMorningStar · 26 May 2009 at 11:05

it's ram more than cpu i would say. with a 4890 with 1gb of gfx ram and 2gb in your system already you will need to upgrade your OS to a 64bit version to use more ram

Greebo · 26 May 2009 at 11:53

Duran said:
bottlenecking is mostly an urban legend

Not true. There are plenty of reviews showing otherwise and it certainly was from my experience.

I went from a 3ghz 4200+ x2 to a 3ghz q6600 with a 8800GTS 512 (vastly overclocked) and saw a 12 fps improvement in crysis (from 28 fps to 40 fps) at 1680 x 1050 so with a slower cloecked 4200+ and a much faster card then the difference will be even more noticable.

Framerates improved in all my games, not just crysis.

Here's some relevant info:

http://www.benchmarkextreme.com/Articles/CPU Bottleneck Analysis/P2.html
http://www.legionhardware.com/document.php?id=807&p=2

And the best till last:

http://www.legionhardware.com/document.php?id=770&p=2

I know the 4870x2 will be quicker than your 4890 but not by huge margins. Just look how the 4200+ x2 cripples the 4870x2 in the games. In most you are only getting 50-60% of the framerates that a 3ghz Intel quad will give you, never mind a 4ghz Intel quad.