darkhorseporter

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ok. heres the deal. I need to upgrade, and want to oc the hell out of an a64 3000+ (s939). I hoping that I'll be able to get 2.6 out of it, but I know that depends on the chip that I get.

I'm thinking about the MSI k8n platinum SLI, and a zalman 7700cu

My question has 2 parts:
1. what RAM should I get?
2. I'm poor, and might need to get 512 now and 512 later. do I need matched pairs? I know that balistix dont come matched. how about unmatched g.skill, corsair, etc...? (obviously I mean same band/model, just bought at different times)

thanks a ton,
Adam
 

BrentUnitedMem

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Your board supports dual channel. With only one DDR400 module your memory bandwidth is only 3200MB/s. With two DDR400 modules your memory bandwidth is 6400MB/s.

If you want to OC the hell out of it(get better performance), you'll need to run dual channel my friend.

It is ideal to run matched pair in dual channel. Memory module brand is not important, but you want to make sure both are rated at the same speed and same number of chips/module.
 

darkhorseporter

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I understand that dual channel is a must, but I just wanted to be sure that I didn't have to plunk down $275(USD) all at once for good ram, but that i could get some now, then get the rest later to oc with. I'm kinda at the end of my rope with my current pc (P3-450 katmai) and need to upgrade, but have not enough cash to do the whole shot right now.

I also need to know if I can reasonably expect to get 290 fsb out of the ram you guys recommend, cause if I'm not mistaken thats what I'll need to get a 3000+ (with a multiplyer of 9) to 2.6 (9x290= 2610), assuming I'm using a 1:1 ratio.
 

over_c

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I just got some Patriot XBL PC3200 from newegg for about $220 for a matched 2x512MB PC3200 pair. It is running at 2-2-2-5 on my Asus P4P800 board. It is built with the Samsung TCCD chips and I hear it overclocks very well. However, I have no personal experience with that.
 

silverpig

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Get 1 GB of Corsair or Kingston value ram and use a divider. If you have a little more $, then go for some stuff with better timings, but don't worry about the bandwidth. A64 doesn't lose much performance at all by running async ram as it's not bandwidth starved.

s signature has been formatted to fit your scr
 

Crashman

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Reality is different from theory: A single stick gives me just under 3GB/s, dual channel gives me around 4.8GB/s, according to benchmarks, on a P4 system.

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BrentUnitedMem

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Yes, of course theory is different that reality. Goes without saying. Usually, products are advertised by their theoretical performance. It provides a standard. There is no standard when we are talking about real performance.

But we all know that already.
 

darkhorseporter

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briefly, what is the technical explaination of running a divider. I understand that 1:1 means that the ram speed and cpu fsb are equal. I assume that running a divider allows the ram to run slower than the cpu, but what is really going on? and how much performance is lost? 5%? 10%?
 

darkhorseporter

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so essentially, any ram that can clock 220-ish will see an a64 up to 290 fsb without significant performance loss. Assuming you can tighten the timings of the cheaper stuff, why bother with expensive ram?

think this stuff will cut it?

Corsair Value Select 512MBx2 DDR PC-3200 $140 (USD)