DDR2-1066 with Athlon X2?

[DJ Bobo]

Hi,
I'm planning to build a new system in the next few weeks based on an AMD Athlon X2 processor. I will go for an AM2+ motherboard for future upgrade possibility to Phenom processors, so I'm thinking about getting DDR2-1066 memory, so that I won't have to change the memory when I upgrade.
Can I use such a memory or will it cause problems?

[dat720]

Technicly you can use any memory that is faster than the memory required by your processor, but it does depend, some motherboard's MSI in particular can be picky about the memory they use.

Most of the time you should be fine, but if you have problems just take the memory back to the store you baught it from for a swap.

[CWR03]

More than likely a new motherboard that supports a Phenom processor will require DDR3 memory anyway - I just built a system myself, and went for a good deal on DDR2 RAM (got 2 GB of dual-channel Corsair, fastest the board supports, for $40 from Tiger Direct).

[burfadel]

If you overclock faster RAM is definitely an advantage. The other consideration is latencies, DDR2-800 with good default latencies can be better that DDR2-1066 with 'loose' latencies. This is especially true if you overclock but the RAM (due to divisors etc) only runs at say, 932Mhz. Although latencies can generally be made tighter than stated by the manufacturer, it is still advantageous to get the best possible for the money you wish to spend.

Also consider the voltage required by the RAM. Some RAM requires up to 2.3V to run at ddr2-1066, and some boards only go to 2.1V or so. The DDR2 spec is only 1.8V. You can get DDR2-1066 RAM at 1.8V. The advantage with the 1.8V ram is that if you can up the voltage to 2.1V, as long as you have reasonable cooling you can generally push it even faster :)

[Blue_MiSfit]

Latencies don't matter - and neither does RAM frequency for that matter.

The difference between cheapo DDR2-800 and "fast" DDR2-1066 (even the expensive low latency types) is almost nothing in every benchmark I've ever seen.

The only time really fast RAM is worthwhile is if you're bent on overclocking heavily, retaining a 1:1 FSB:RAM ratio (which isn't even a huge deal IMO).

Save your money, get DDR2-800 :)

~MiSfit

[DJ Bobo]

The question was actually more about the compatibility of the DDR2-1066 memory with the memory controller of the Athlon X2 processor, which supports up to DDR2-800 "only".
Will the Athlon X2 processor deny the service at all, or will just run the memory with the default frequency (which would be 714MHz for a 2,5GHz model for example)

As said, the thing about me wanting to use DDR2-1066 is that I may need it for a future upgrade to the Phenom processor which supports these by default.

[Sharktooth]

yes, they work. you have to ensure the MB supports them though to run them at 1066 otherwise they will run at 800MHz or may not work at all.
the latest asus M3Asomething and foxcon A79A-S do support them: http://www.tcmagazine.com/comments.php?shownews=21042&catid=2 and here: http://www.tcmagazine.com/comments.php?id=20103&catid=2