Noob asking for memory advice

MadHarry · Post by **MadHarry** » Fri Feb 05, 2010 5:42 am

Hi, I've decided to buy a ASUS M4A78T-E for a low power Phenom II (good reviews, like the manufacturer, reasonable price, IGP may be handy).

But I'm having trouble picking some DDR memory for it. I can't find the memory I pick in the ASUS memory qualified vendor lists and suspect the list is a tad out of date. I can use the Crucial, OCZ, G.skill, Patriot etc memory selectors but am not sure of their selectors reliability and that they seem to regulary select really high latency RAM all the time (limitation with product range or motherboard?).

I originally want some 1333MHz, low latency, low voltage DDR3 but might have to widen my choice. My questions are,

1. Will I notice the difference between timings something like 8-8-8-20 and 9-9-9-24? The slower MHz / lower voltage parts I seem to find don't improve much in latency.

2. Will I notice that much performance difference in 1066MHz, 1333MHz and the overclocked 1600Mhz ones?

3. What would be the power consumption differences would be in say 1.8V and 1.5V and 1600Mhz and 1333Mhz? Are we just talking a couple of Watts or tens?

Regards,

M

P.S. PC would be used for compiling code, some gaming and file compression.

andymcca · Post by **andymcca** » Fri Feb 05, 2010 6:29 am

Generally speaking your memory consumes under 10W no matter what, and under 5W unless you have some crazy setup. This was true for DDR2, anyway, and I assume has not changed much for DDR3. The higher voltage and higher clock speed RAM will generally use more power, but it is hard to say without actually buying both and testing.

As for the timings, it depends what you are doing, and where your bottlenecks are. I'm not sure what the demands are for compiling large projects (and suspect it has to do with how well the compiler can parallelize via loop unrolls, etc), but for games and compression tests you might see a couple percentage points difference in performance.

Vicotnik · Post by **Vicotnik** » Fri Feb 05, 2010 6:35 am

I say unless you're a 3DMark score hunting overclocking type of guy, get the cheapest 1.5v "value" RAM from a manufacturer you trust.

No non synthetic benchmarks I've seen comparing RAM timings have shown any significant performance difference.

MadHarry · Post by **MadHarry** » Mon Feb 08, 2010 5:22 am

Thanks for your replies andymcca and Vicotnik. This confirms what I suspected. The RAM can't take up too much power as they would have big heatsinks and pipes etc. As for the latency issue my good old 2-2-2-5 DDR wasn't really noticable except for benchmarks and possible UT 2004. It might have squeezed 2 extra fps out of it but I didn't accurately measure it at the time. It is just that these days, tRAS of 24, sheesh!

Anyway gonna order some RAM tonight and not be so fussy this time. All I got to do now is pick a case, heatsink and fans. Will have a look at the useful articles and reviews here.

jessekopelman · Post by **jessekopelman** » Mon Feb 08, 2010 1:44 pm

MadHarry wrote:It is just that these days, tRAS of 24, sheesh!

You can't really compare latencies between DDR and DDR2, let alone DDR3. 8-8-8-20 @1333 isn't bad at all. Look at it this way, the tRAS might seem high, but what about the 1333 part? Your 2-2-2-5 DDR was probably 400 Mhz, or maybe even lower.