Which is better, a 4GB kit (2x2gb) or 2 2GB(2x1) kit?

[jrick]

I'm trying to replace my 2gb defective ram with a 4GB ram.

 

The rams guaranteed-compatible with my motherboard (P5N-E SLI) includes the TWIN2X2048-6400 and TWIN2X4096-6400C5DHX.

 

Now which is better? 2 set of 2gb kit or a 4gb kit?

Would 2 sets of 2gb kit even work?

 

Also, is the built-in memtest on Windows Vista good enough?

[trackrat]

One tested and approved 4 BG. kit is what you want. Two kits are never guaranteed to work even if identical modules.

 

From the Corsair main website Memory Finder option, the link below shows the tested and approved Corsair RAM available for your mobo.

 

http://www.corsair.com/configurator/product_results.aspx?id=56586#other_modules

 

I prefer to run Ramtest 86+ from a bootable CD.

[jrick]

supposed i have gotten than 4GB kit, what if i want to upgrade to an 8GB, do i need to buy an 8Gb kit to replace that 4GB?

[trackrat]

Ideally yes if you want to upgrade to a greater quantity of RAM and be certain the RAM will function properly, you would buy one tested, approved kit for your application.

[lordraptor1]

although a board has 4 ram slots doesnt neccesarily mean you should populate all 4, i have found that for 32 bit O/S 2 gigs is plenty and with a 64 bit O/S 4 gigs is preffered. this is of course unless you are running a board newer than a 775 or am2 socket. i am running a 2x2 gig kit of 6400 C4DHX (or at least i will once my rma is finished because of a stick failing) on my evga 780i sli mobo.

[trackrat]

The optimum quantity of RAM is based on both the O/S and software. A typical 32-bit Windows O/S can only access 3 GB. where as a 64-bit O/S can typically access up to 128 GB.

 

If you are doing photo/video editing or CAD then 8 GB. or more may be of benefit depending on the O/S and software you use.

 

http://msdn.microsoft.com/en-us/library/aa366778(VS.85).aspx

 

System performance is usually better if you can use just two memory slots, (dual channel) vs. four as the use of four slots typically requires lower frequencies and longer latencies to prevent data errors. In triple channel systems three channels is better than six, for the same reasons as in dual channel systems.