Higher CPU freq. Vs higher Ram Freq. - Overclock.net

ryboto · 09-15-07

I just upgraded to 4x1gb ram. I'm using a specialty ITX power supply, so I don't want power consumption to go up...regardless of my reasons, I'm curious what would be better in terms of performance.

X2 4000+

1.) 2.1ghz
DDR2-700
or

2.) 2.0ghz
DDR2-800

Obviously, it would make more sense to do what I was doing prior to the ram upgrade, which was 2.1ghz/DDR2-840, but because it would up the power draw I don't want to risk pushing the power supply.

dralb · 09-15-07

I would say the 800/2.0. I don't think 100mhz would get you more than 50mhz RAM speed. Think of it percentage wise. You are gaining 5% CPU speed or 25% RAM speed (I think, my math skills are fading, lol)

microman · 09-15-07

wait are you really running that computer on a 120w psu??

StormX2 · 09-15-07

Faster memory in this case would be benneficial for sure
and you should be able to overclock it a little bit more easily without uping voltage.
try to get the tightest timings possible but you shoudl be very happy
100 mhz gain is so small thts its not worth the increae in memory bandwidth

**ericeod** · 09-15-07

I would have to disagree from the above posters because you can tighten the ram timings at the lower speed. AMD systems benefits a lot from tighter timings! This is because the memory controller is on-die, so the CPUs dont have to share memory bandwidth with eachother. This is why Intel CPUs benefit from higher speeds while AMD chips benefit from tighter timings.

Source: Tech Target

StormX2 · 09-15-07

thats mroe true in the case of DDR1 machines

with DDR2 however the performance is pretty close with tighter timings or higher OC

so either way he chooses will be pretty close, but the higher memory bandwidth will most likely prove to be smarter choice.

**ericeod** · 09-15-07

Quote:

Originally Posted by StormX2

thats mroe true in the case of DDR1 machines

with DDR2 however the performance is pretty close with tighter timings or higher OC

so either way he chooses will be pretty close, but the higher memory bandwidth will most likely prove to be smarter choice.

I know it applies to dual cores, but how does the DDR 2 compensate for the cores sharing the bandwidth, the memory controller hasnt changed on the AM2 CPUs has it (besides the inclusion of support for DDR 2)? I'm only asking because I've only worked on the S939 CPUs.

Source: AnandTech

Quote:

As you can see, given almost a 9% increase in memory bandwidth, we saw similarly small increases in overall performance. It would seem that the Athlon 64, at its current clock speeds, just simply isn't starved enough for memory bandwidth to benefit from an increase in bandwidth. You'll also see that the areas where faster DDR memory helped back then are pretty much the areas where DDR2-800 is showing gains today.

Based on our results from back then, if a 9% increase in memory bandwidth doesn't increase performance tremendously, then the 35% increase in bandwidth we see with DDR2-800 on AM2 shouldn't yield any more of a performance increase. Or simply put, yes, our AM2 performance numbers make sense.

ryboto · 09-15-07

Quote:

Originally Posted by microman

wait are you really running that computer on a 120w psu??

yes, I am, it's a 200W design, but the manufacturer say there are thermal limitations, and since most users will use it in a low airflow ITX system, they just rated it for 120W. It's been working for me fine without fail.

As for the answers here....I'll have to try a few things. I think I know what I'l try.
-2.1ghz(10.5x200), DDR2-700, tight timings(3-4-4-12)?
-2.0ghz(10x200), DDR2-800 4-4-4-12

I could do a quick performance test between the two. A ram bandwidth test using...Everest? And maybe a CPU test, like super pi?

I hate to keep adding questions, but what settings would you recommend for 4x1gb DDR2-800 Crucial Ballistix? I've got them running on 2.1v now. The next setting in the BIOS is 2.35v, kinda silly bios. The original 2gb were fine running DDR2-840@ 2.1v. What do you think they can handle as far as timings at DDR2-700?

zaccy001 · 09-16-07

GET A NEW PSU... youll be sory when it ****s up and ****s everything else up along with it..

ryboto · 09-16-07

Quote:

Originally Posted by zaccy001

GET A NEW PSU... youll be sory when it ****s up and ****s everything else up along with it..

that's intelligent! Funny, the system only draws 134W from the wall when i game, and 100W when I fold. If you assume the power brick is ~80% efficient, that's only around 110W DC load. hahha...this coming from someone with a Thermaltake? Your system probably wouldn't use more than 250-300W under full load.

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Higher CPU freq. Vs higher Ram Freq.

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