memory 333 / 400 speed question

[blacknight31k]

I would like to upgrade my memory up to 2gig.

here is my spec's so i can explain my question
a8n-sli premium, bios 1009
amd fx55
2x512 pc3200 crutial ballistix (6,2,2,2,2t)@2.8v
ati x1900xtx
wd 250 sata2 hd
win xp pro sp2

My mobo has 4 mem slots a1,b1,a2,b2. If i use all 4 slot it will revert back to 333 speed.

My question: Is there much diff between 400/333 speed? Should I buy 1gig stick and use only 3 slots in order to keep the 400 speed or should i just buy 2x512. My manual say that a1,b1 must equal a2,b2. Im assuming that to mean: a1(512),b1(512)=a2(1024) am i correct or am i missing something?

Thanks in advance for any help

[Sterling_Aug]

What it means is that if a1 and b1 has two sticks of 512 MB each, then a2 and b2 must also have two sticks of 512MB each.

You can sell the two sticks of 512MB and buy two sticks of 1GB each, or you can leave the system as is now. Going from 1 GB to 2 GB isn't going to be a benefit unless you run lots of big and RAM consuming programs like video editing.

Dropping from 400 MHz speed back to 333 MHz would be noticeable, but not a deal breaker. I would stay with as fast of a speed as possible.

[blacknight31k]

Thanks for the reply. You make better sence than my manual. hehe I play bf2 which is a memory hog, and noticed that im using all 1gig and some pf after i play for extended periods.

Im going to look into selling the ram or maybe just put it in another system i have and get 2 sticks of 1gig.

Im also planning on a new build towards the end of the year and the ddr mem will not be upgradable since ddr2 has become the standard.

thanks again

[Sterling_Aug]

Make sure you check for compatible RAM for the system before you buy it.

I prefer to go right to crucial.com or kingston.com and select the RAM using the website configuration tools. That way they are guaranteed to work or you can return it.

[Peter M]

What it means is that if a1 and b1 has two sticks of 512 MB each, then a2 and b2 must also have two sticks of 512MB each.

No they don't. The setup doesn't have to be 4-way symmetrical, and there are no benefits at all if it is. Having e.g. (1G+512M) DIMMs on channel A and the same (1G+512M) on B is just as good, performance wise, for 3G total.

Dropping from 400 MHz speed back to 333 MHz would be noticeable, but not a deal breaker. I would stay with as fast of a speed as possible.

It makes a big difference in memory throughput benchmarks (obviously), but very little actual difference in real life applications - with a few exceptions.

Want to know whether /yours/ are affected in a noticeable way? Visit your system BIOS, set the RAM speed limit to 166 MHz and see for yourself, with the stuff you have now.

[blacknight31k]

the way my setup is right now is:
channel A:a1(512),a2(0)
channel B:b1(512),b2(0)
that way its running in dual channel

what i thought i could do is run:
channel A:a2(1g),b1(0)
channel B:a2(512,b2(512)
that is what i thought i could do, but i am not sure, and would still keep 1g on each channel. Tha would keep it at the 400 speed

Quoting the manual "for dual-channel configuration, the total size of memory module(s) installed per channel must be the same for better performance."
(dimm_A1+dimm_A2=dimm_B1+dimm_B2)

the way i took that as long as the total of both channels are equal 2g that it would work, 1 stick in channel A and 2 sticks in channel B

thanks again

[Peter M]

Your planned setup wouldn't run at best dual channel speed. Newer Athlons do support that asymmetrical population, but with less throughput than proper dual channel.
Capability for fully parallel operation is not about total size. It requires individual ranks ("DIMM sides") on both channels to be absolutely identical in geometry and position.

With two DIMMs on channel B, you'd get the degraded timings anyhow, so no actual gain compared to filling all four slots.

[blacknight31k]

ok i understand now what u mean

so should i get 2 sticks of 1g each or 2 more of the 512 sticks and just let if revert to the 333 speed???

thanks again

[Peter M]

Yes. If your current DIMMs, or the new ones you buy, are single-sided, then a newer Athlon will even let you run DDR400 with 2T timing.

Like I indicated above, the overall speed loss from slower RAM isn't as much as the hype would make you think ... and of course you lose much more performance if you don't have enough RAM to begin with, whatever the speed.

[blacknight31k]

THANKS ALOT, I APPRECIATE ALL THE INFO. I WILL PROBABLY BUY 2 STICKS OF 1G EACH.
THANKS VERY MUCH FOR YOUR HELP

[Peter M]

YOU'RE WELCOME. CAN WE STOP SHOUTING AT EACH OTHER NOW?

Thanks. ;)

[blacknight31k]

hey everyone, this is blacknights wife, he had to go back to work so he is unable to get on the net there... he will be back home in 10 days. i just wanted to make shure all of u knew he is not ignoring u at all.