CPU cache and Game Performance

[x2 3600 rules sazakky]

How much difference would it make to games if I used a 256kb cachex2 dual core cpu and 512kbx2 dual core cpu.
Would it be subtle or profound difference

 

[error8]

What cpus are you talking about?

 

[x2 3600 rules sazakky]

say the x2 3600+ 65nm edition and 90nm edition

 

[error8]

Ok, so we are comparing these two:
3600 X2 90nm, 2ghz, 256X2 l2 cache with 3600 X2 65 nm, 1,9 ghz, 512X2 l2 cache.

Well at stock clocks I guess they are pretty similar. The 90 nm cpu wins at frequency and looses on l2 cache, making them quite about equal, although the brisbane might be a bit faster overall. Once you start overclocking, the 3600+ x2 on 65 nm will hit pretty easy 2,8 ghz, topping 3 ghz with voltage increase, while the other one will struggle to touch 2,6 ghz, even with high voltages.

So, if you are thinking which to buy, then the 65 nm cpu is clearly the best choice ( better overclocking, lower power consumption).

Level 2 cache on AMD cpus doesn't seem that important, but I've read reviews where in games like Half Life Episode 2, higher L2 cache really increased performance over AMD chips with half the cache. So...

 

[BTRY B 529th FA BN]

From a review I read a while ago (can't find it) In UT3, going from 3mb L2 cache to 6mb L2 cache, there was a 14% increase in frame rates @ 1280x1024 other results were between 4-10%

 

[error8]

Originally posted by: BTRY B 529th FA BN
From a review I read a while ago (can't find it) In UT3, going from 3mb L2 cache to 6mb L2 cache, there was a 14% increase in frame rates @ 1280x1024 other results were between 4-10%

We are speaking only about AMD cpus. The cache doesn't have the same impact in performance on AMD chips like it has on Intel ones.

 

[RallyMaster]

Originally posted by: error8

Originally posted by: BTRY B 529th FA BN
From a review I read a while ago (can't find it) In UT3, going from 3mb L2 cache to 6mb L2 cache, there was a 14% increase in frame rates @ 1280x1024 other results were between 4-10%

We are speaking only about AMD cpus. The cache doesn't have the same impact in performance on AMD chips like it has on Intel ones.

Maybe because AMD chips have so little L2 cache compared to Intel chips? In one, you're comparing 512KB to 1MB. In the other, you're comparing 3MB to 6MB. That's a huge difference.

 

[Gikaseixas]

Originally posted by: RallyMaster

Originally posted by: error8

Originally posted by: BTRY B 529th FA BN
From a review I read a while ago (can't find it) In UT3, going from 3mb L2 cache to 6mb L2 cache, there was a 14% increase in frame rates @ 1280x1024 other results were between 4-10%

We are speaking only about AMD cpus. The cache doesn't have the same impact in performance on AMD chips like it has on Intel ones.

Maybe because AMD chips have so little L2 cache compared to Intel chips? In one, you're comparing 512KB to 1MB. In the other, you're comparing 3MB to 6MB. That's a huge difference.

correct, AMD needs to hurry with those new versions (6/8mb of cache) so we can see how well games can run on them

 

[Munky]

Originally posted by: RallyMaster

Originally posted by: error8

Originally posted by: BTRY B 529th FA BN
From a review I read a while ago (can't find it) In UT3, going from 3mb L2 cache to 6mb L2 cache, there was a 14% increase in frame rates @ 1280x1024 other results were between 4-10%

We are speaking only about AMD cpus. The cache doesn't have the same impact in performance on AMD chips like it has on Intel ones.

Maybe because AMD chips have so little L2 cache compared to Intel chips? In one, you're comparing 512KB to 1MB. In the other, you're comparing 3MB to 6MB. That's a huge difference.

I recall when AMD x2 cpu's had 2MB total L2 cache, and even then there wasn't much difference from 2MB to 1MB in gaming performance.

 

[aka1nas]

Originally posted by: RallyMaster

Originally posted by: error8

Originally posted by: BTRY B 529th FA BN
From a review I read a while ago (can't find it) In UT3, going from 3mb L2 cache to 6mb L2 cache, there was a 14% increase in frame rates @ 1280x1024 other results were between 4-10%

We are speaking only about AMD cpus. The cache doesn't have the same impact in performance on AMD chips like it has on Intel ones.

Maybe because AMD chips have so little L2 cache compared to Intel chips? In one, you're comparing 512KB to 1MB. In the other, you're comparing 3MB to 6MB. That's a huge difference.

That, and also the IMC offsets the performance cost of going out to RAM somewhat, IIRC.

 

[BTRY B 529th FA BN]

Originally posted by: error8

Originally posted by: BTRY B 529th FA BN
From a review I read a while ago (can't find it) In UT3, going from 3mb L2 cache to 6mb L2 cache, there was a 14% increase in frame rates @ 1280x1024 other results were between 4-10%

We are speaking only about AMD cpus. The cache doesn't have the same impact in performance on AMD chips like it has on Intel ones.

Aside from the on-die memory controller, how so?

 

[x2 3600 rules sazakky]

lets say for example, in crysis, how much difference would 256kbx2 and 512kbx2 make.

 

[x2 3600 rules sazakky]

i dont knoiw what your taling about as i overclocked my 3600x2 90nm to 2.7ghz easily

 

[error8]

Originally posted by: x2 3600 rules sazakky
i dont knoiw what your taling about as i overclocked my 3600x2 90nm to 2.7ghz easily

Well that's great. I've read some reviews about it and it touched 2,6 ghz with lot of pain. My 3800+ X2, which is just like yours but with 2x512 kb cache, also got to 2,6 ghz struggling.
So, you've got yourself an above average overclock for that chip.

 

[lopri]

I think it also heavily depends on how the game in question is coded. Generally, games that are not well-coded, or based on messy engines tend to benefit more from larger L2. Modern, DX9/DX10 titles as well (heavy data set).

 

[GundamF91]

AMD used integrated memory controllers, so L2 cache size doesn't impact it nearly as much as say Core2 where the cores required bigger L2 to compensate.

 

[desolate]

Cache is infact one of the reasons I upgraded from an Intel Core 2 Duo E4300 to an Intel Xeon X3210 w/ 8MB Shared Cache...although it doesn't make to much of a difference, every little bit helps. I'd have to agree with everyone else though, on AMD platforms it's a whole different story.

 

[x2 3600 rules sazakky]

So, if AMD is a different story, how mcuh of a difference would the two CPU's make in CRYSIS

 

[RallyMaster]

Maybe 2-5 fps.

 

[imported_Woody]

The X2 will be struggling with Crysis anyway so relative framerates will be dependent on a great many other factors. I have a lot of experience with the Athlon 64 socket 939 and the Athlon XP series and in my experience, the way AMD names the chips is a pretty close indicator of relative performance. You find a lot of AMD chips with different specs but the same name because AMD has determined they perform very close. As a rule you find a 0.1 GHz speed difference equates to about 512KB cache size difference.

If you plan to run the chips at stock speed just get whatever's cheaper. If you plan to overclock get the newer chip with the larger cache since you will probably overclock higher than the other one.

 

[RallyMaster]

Originally posted by: Woody
The X2 will be struggling with Crysis anyway so relative framerates will be dependent on a great many other factors. I have a lot of experience with the Athlon 64 socket 939 and the Athlon XP series and in my experience, the way AMD names the chips is a pretty close indicator of relative performance. You find a lot of AMD chips with different specs but the same name because AMD has determined they perform very close. As a rule you find a 0.1 GHz speed difference equates to about 512KB cache size difference.

If you plan to run the chips at stock speed just get whatever's cheaper. If you plan to overclock get the newer chip with the larger cache since you will probably overclock higher than the other one.

Fixed.

 

[Davegod]

this is the best I can find, x2 4400's scoring -

Quake IV:
1mb 81.40
512kb 75.40

Serious Sam 2:
1mb 111.30
512kb 102.90

approx 7% improvement, more than I would expect. Crysis is even more GPU bound so my assumption is less benefit will carry.

If you want to compare both exact cpus in Crysis, you have three easy options: spend more time googling than me, have better google skillz or go buy both cpus and run benchies.

 

[RussianSensation]

Originally posted by: x2 3600 rules sazakky
lets say for example, in crysis, how much difference would 256kbx2 and 512kbx2 make.

Probably immaterial. Crysis is a very gpu limited game - See Graph below

 

[imported_Woody]

LOL! fixed....

I went back and edited...thxs

One day maybe right? My first computer had only 4K RAM.