• Competitor rules

    Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.

CPU Bottleneck

Chronictank

Chronictank

Chronictank

Soldato
Joined
12 Jan 2006
Posts
2,547
Hi,
i know it has been prooven this bottleneck exists i was just wondering if someone could explain why this bottleneck occurs as i cant find any reasonable explanation using google.
I understand in the old days a cpu bottleneck would occur when you had a super fast graphics card and the cpu couldnt give it enough frames to render.
I cant see how this is the case nowdays as (for example), when running crysis my CPU bearly reaches over 60% so how could it be struggling to give enough frames? It very obviously is not having to do too much work per tick, so where is this bottleneck coming from?

Now the other way i see it is that there is a bandwidth limitation whereby the cpu i can only give so many frames and it has reached its roof, but this rationale falls down on the fact that if you increase the clock speed then the performance increases :confused:


Cheers in advance
 
surely everyoen wont have memory bandwidth limitations?
although more to the point if there was a bottleneck created by memory why does the graphic performance increase with an increase in clock speed
 
Unless you have a Black Edition (AMD) or Extreme Edition (Intel) then you have to ramp up the FSB, which means the memory clocks up with the CPU.
 
Ah that would make more sense (running 1:1 atm @ 357Mhz), so its not the fact you increase the cpu speed but because you increase the memory speed, is that correct?
 
If your vram was exceeded and main memory was being used for textures by the graphics card then I could see memory bandwidth being vital like that, I had not noticed but Im about to switch from 266fsb to like 400 so I will test before and after with the same CPU speed to see

In the crysis gpu test I do notice a lot of judder and obviously it runs faster in the second and third runs
 
The term bottleneck just referes to what part of your system is the limiting factor, remember that the bottleneck will be different depending on the software used and the (in the case of games) resolution used. An RTS running on a single core 2ghz CPU with 4gig ram and a 8800gtx at 1280x1024 will be bottle necked by the CPU. Change that res to 1920x1200 with 16xAA/AF and the GFX card will take more of a hit so may become the bottleneck.
Run some video editing software with vista on a quad core machine at high res and an 8800ultra but with 1gig ram and the ram will be the bottle neck.
 
You must log in or register to reply here.
Back
Top Bottom