DDR2800 2GB DIMMs for ASUS P5WDG2 WS Pro

Nedkt

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I found this on Kingston:
4GB 533MHz DDR2 ECC CL4 DIMM (Kit of 2):
Standard 128M X 72 ECC 533MHz 240-pin Unbuffered DIMM (SDRAM-DDR2, 1.8V, CL4)


What are the ins and outs of high capacity RAM on an ASUS P5WDG2 WS Pro? I see no DDR2 800 floating around at all. I would like to max out this MOBO with 8GB but I would rather do it all at once (or at least not have to later dump lower capacity RAM).
 

darkstar782

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Firstly, what are you doing that needs 8GB of ram? There are several factors to note.

1. Windows XP x32 only supports 4GiB of RAM address space. Some of this is reserved, so you will only actually be able to use 3.5GiB or so.

2. 32 bit processes on ANY version of windows, even x64, can only ever be allocated 2GiB each. This means even on Windows XP x64, unless your application is 64bit (very few consumer apps are, if the one you are planning is then you will know about it), then it will NEVER see more than 2GiB, leaving 6GiB for Windows and background apps :s

Now, assuming thats all OK for you....

Yes, high capacity chips are both slower and overpriced. Those 2GiB DIMMs are ECC, meaning they are error correcting, this is good, but will slightly increase latencies. You wont find anything faster than that 533MHz in those capacities.

Unless you have some specific task in mind then in almost all cases you'd be MUCH better off with 4GiB of DDR2-1066 CL4 RAM, which will be over twice as fast and probably cheaper.
 

Nedkt

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1. Windows XP x32 only supports 4GiB of RAM address space. Some of this is reserved, so you will only actually be able to use 3.5GiB or so.
Yup, I was planning on doing this both for the FreeBSD I am setting up on one hard drive and Vista, which will resolve the Win32 memory hole issue, when it comes out. But that said, you have a good point.

2. 32 bit processes on ANY version of windows, even x64, can only ever be allocated 2GiB each. This means even on Windows XP x64, unless your application is 64bit (very few consumer apps are, if the one you are planning is then you will know about it), then it will NEVER see more than 2GiB, leaving 6GiB for Windows and background apps :s
I actually wanted to play around with RAM disks and a few other things. But, I see this memory is ridiculously expensive.

Unless you have some specific task in mind then in almost all cases you'd be MUCH better off with 4GiB of DDR2-1066 CL4 RAM, which will be over twice as fast and probably cheaper.
I was thinking the same thing after an afternoon of reading up.
 

darkstar782

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Fair enough then :)

I didn't mean to come off as condescending, apologies if I did

I've had similar thoughts myself about making huge Ramdisks, 8GiB is enough for a 4GiB 'Windows' ramdisk and 4GiB of memory free still... but it seems like the only way atm is using things like Gigabytes I-Ram device, which kinda defeats the object by being on a SATA interface imho....

If only we could get a consumer boards supporting FB-DIMMs then Quad Channel interfaces and 8+ RAM sockets would be feasable...