Well, my system's old now, but works like a charm. I was looking to upgrade the ram, and have a little problem:

SysteM: amd 3800+ x2. (939)
Mobo: msi k8n neo 4 platinum (nforce-4 ultra chipset)
MSI 8800GTX
and system use: gaming, photoshop, and gaming!
OS: Vista32, XP32
Current Ram: 2x512 - Corsair VS513MB400 DDR-400 = 200MHz @ CL=2.5, tRCD=3, tRP=3)

What i have available to upgrade: Kingston valueSelect Ram, prolly 2.5-3-3 or 3-3-3 ... cant say, coz its with a frnd.

Question(s):
Will 4x512 work? (for total 2g ram).. with those different timings?
Or Suppose if the timings are same, then two corsairs and two kingston... wud they be ok togather?
OR Should i go for 2x1Gb Kingston, also available. And get rid of my 2x512 corsairs.

Ive read that using 4x512 on amd reduces 400 to 333, and there is a slight performance drawback in 4x512 as compared to 2x1g. BUT that is not to big a drop... so what will it be?

A frnd of mine just checkd his mem speeds and got this result:

4200+ with ddr2 (533mhz).. ram timings are 3-3-3-9, 4-4-4-12 and 5-4-4-12 at 400, ~533 and 533 mhz.

Your current ram looks like Corsair Valueselect(i assume you mean VS512MB400) DDR 400(i have some in works great in my server )

But your friends ram is DDR2. DDR2 does not fit in a DDR board without a large hammer, and even then it will not work.

In the case of different timings. the board will run all the ram at the timings of the lowest stick. so thats not a issue, but ddr2 on a ddr board is.

2 sticks of 1 gig(2 gigs total) is the best bet for performance.

xbitlabs has an old but good article comparing 4x512 VS 2x1GB:
http://www.xbitlabs.com/articles/m [...] b-ram.html

Btw long time no see nuke glad to see u again mate

@nuke: i know abt the ddr2-wont-fit-in-ddr thing.. however, it was interesting to note the timings.. anyways, still, will cros-vendor sticks work togther? and Esp if they have diff timings?

@Maizar: thanx for the link Some good info there

different timings work ok 99% of the time. I have 2 DDR2 667(rated 5,5,5,15) and 2 sticks of DDR2 800(4,4,4,12). With a little voltage it all runs at 667 4,4,4,10.

The timings are looser on DDR2 and even more so on DDR3. They compensate with faster speeds. in some benches DDR 400 can outdo DDR2 800. but in general the extra speeds and optimization in the memory controller make up for the latency difference.

I'm currently running 2gigs, 2x512MB corsair and 2x512MB patriot.
The corsair work as low as 2-2-2-5, and the patriot can barely do 2.5-3-3-7
Both are running at 2.5-3-3-7 with no problems at all, dual channel and even slightly overclocked.

As long as your motherboard accepts both brands and they can run at timings supported by both, there shouldn't be a problem.

Splendid! IF they work, then thats good Well, the link Maziar gave, even tho old, shows that 2x1g is better than 4x512, in some cases. So, ill see what i can come up with, and will post the final results of what ever i get so all can compare

PS: Im into overclocking cpu/gpu but havent tried rams as yet.. seems a bit too complicated / risky.. and needs a lot more homework

When you oc the cpu its done with the fsb. So you may need to use a memory multiplier to drop the ram speed. The overclocking will then bring it back to its rated speed.

lets see, if i increase reference clock from 200 (stock) to 220, i go from 2.2G to 2.42G (cpu multiplier 11x) I also increase HT bus frequency from 1G to 1.1G (HT multiplier 5x) ... and memory bus freq (ddr) from 400 to 440.

So by going from 400 to 440, i wud need to lower what timings to what new numbers.... ?

@nukemaster, help me out please

you would have to test, some ram runs at 440 others will not. There is a multiplier that can drop the ram speed to 333 then your additions will still be under 400...

@ Maziar, i am still around.

to c0d3r:
No problem mate glad i could help u

To nuke:
Glad to hear it

Well, i went for the 2x1g config.. and the ram shows 4-4-8 @ 200mhz.

If i lower the ref clock to 133mhz, from 200, it runs stable on 3-3-6 ...

SO any more suggestions to try out ?