PC2 5300 or 5400.. and other Q's about DDR2

[qwertycopter]

I have a few questions about DDR2. Oh, and these questions are not being asked in consideration of overclocking, only stock speeds:

1) I see both PC2 5300 and PC2 5400 listed on newegg. Both are 667Mhz, so what's the difference?

2) 533Mhz (PC2 4200) is synchronous with a modern 1066Mhz FSB. I've heard it performs better than 667Mhz (non-synch) RAM. Is this true, or only in some cases? The prices are virtually the same, I wonder which is the better buy (if not overclocking)?

3) On to 800Mhz RAM (PC2 6400). How does this perform compared to 533Mhz. It's also not synchronous, but I would assume it would be a lot better because of sheer speed.

 

[misry]

1) I see both PC2 5300 and PC2 5400 listed on newegg. Both are 667Mhz, so what's the difference?

5400 is rated at 675

2) 533Mhz (PC2 4200) is synchronous with a modern 1066Mhz FSB. I've heard it performs better than 667Mhz (non-synch) RAM. Is this true, or only in some cases? The prices are virtually the same, I wonder which is the better buy (if not overclocking)?

Sync RAM is a different animal as is parity and while it performs better in an apples to apples situation, your system is effectively locked into that config.. Always buy the Biggest, Bestest, Fastest you can fit in the budget so you have better upgrade potential.

3) On to 800Mhz RAM (PC2 6400). How does this perform compared to 533Mhz. It's also not synchronous, but I would assume it would be a lot better because of sheer speed.

As always, your application determines how much/ if at all, you will notice an improvement. Assuming nothing has changed but the rated speed of the memory and you are surfing, emailing, etc., very little will change. Now say you had 1G of 533 on one stick, then you take that out and drop in 2 sticks of 512/800 and run it dual channel. You still have just 1G of RAM but now you've just shaved 30 minutes off how long it takes to convert a DVD to an AVI. Keep in mind that it still takes 2 hours for the conversion. Is it worth it?

 

[mpjesse]

The important difference, which MISRy didn't point out, is that most DDR2-533, 667, and 800 all have different timings. The lower the clock speed the better the timings (generally speaking).

If you are not going to overclock, chances are DDR2-533 will perform better than DDR2-667 because it has lower timings. BUT that great varies on the brand and model of RAM you purchase. You can get low timed DDR2-667, but it's expensive.

Besides overclocking there IS a good reason to buy DDR2-667 now: Intel is planning to upgrade the FSB on Core 2 Duos to 1333Mhz. So if you get DDR2-667 now, you can (eventually) get a faster Core 2 Duo and not worry about having to get new RAM.

If I were you I'd get DDR2-667 if you plan to use a Intel based system. If you plan to go w/ AMD, you pretty much need to get DDR2-800 now.