which Ram for a PHENOM II X4 955

[themaster1]

Just bought a new mobo & cpu finally and now i'm looking to buy some DDR3 ram, i'm not sure of which brand or freq i should get though

the cpu:
PHENOM II X4 955 BLACK EDITION (3.2 GHz)
http://en.wikipedia.org/wiki/List_of_AMD_Phenom_microprocessors

the mobo:
ASROCK 970 PRO3 - Chipset AMD 970
http://www.asrock.com/mb/AMD/970%20Pro3/?cat=Specifications

Thanks for your help

[gonca]

Frequency > 1066 or 1333 MHz
Brand > A good or quality brand, don't go cheap not worth the headaches.
Amount > 8 GB minimum if 64 bit OS

[johns0]

Best to get 1600 mhz ram,they are getting very cheap in price.

[aedipuss]

http://www.asrock.com/mb/AMD/970%20Pro3/?cat=Memory

pick a size, then pick a speed(1600 sounds good to me), then go looking on newegg for the lowest price.

[usually_quiet]

If you are going to be encoding video for long periods of time, something from the tested memory list with heat spreaders would be worth considering, if there is enough clearance for them.

[themaster1]

The names given for the Ram are really confusing if you ask me

I've found this one which has a good reputation in the gamer circle i believe:
see here


The phenom II x4 955 can go up to DDR3 PC3-10600 (Socket AM3 only)...100% sure

What's confusing is that on the site above they call it DDR3 PC3-10666 and there is no such ram on earth, i guess it's a typo

DDR3 types:
DDR3-1066 (name: PC3-8500, freq: 533Mhz, real freq: 133Mhz, throughput : 8/5 Gb/s)
DDR3-1333 (name: PC3-10600, freq: 666Mhz, real freq: 166 mhz, thoughput: 10,7 Gb/s)
source: here
There are other types but i believe i must pick one between these two

[jagabo]

DDR3 1600 is probably the sweet spot for general applications. Going faster costs a lot more and delivers very little improvement.

The following tests were run on an Intel Sandy Bridge CPU but the relative differences for AMD processors won't be much different:

http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3

The second pass of x264 shows almost no scaling with memory speed. A few tests show low single digit percent increases above 1600.

[nic2k4]

Check this out, that should ease your mind.

[johns0]

Check this out, that should ease your mind.

The article is almost 4 years old so its outdated with ram technology.

[themaster1]

DDR3 1600 is probably the sweet spot for general applications. Going faster costs a lot more and delivers very little improvement.

The following tests were run on an Intel Sandy Bridge CPU but the relative differences for AMD processors won't be much different:

http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3

The second pass of x264 shows almost no scaling with memory speed. A few tests show low single digit percent increases above 1600.

That's good to know i think i will fall for a pair of PC3-12800 (2x2 gig) to begin as this rig will be dedicated to video encoding mostly

[nic2k4]

The article is almost 4 years old so its outdated with ram technology.

I was being lazy there, I should have pointed out that DDR3 has remained the same since it was first released; clock rate and CAS latency improvements aside. His CPU was released 4 years ago and is closely related to the one in the benchmarked. The memory controller is part of the AMD CPU and for a Phenom II 965, DDR3-1333 is the highest supported clock.

That said, when you read the article, on page 4 & 5 you see that the results for DDR3-1600 & 1333 are very close (I usually disregard results from diagnostic software, I prefer results from actual productivity software). Page 3 shows that the latency has more impact on performance.

The advantage of faster clock RAM is it's ability to run at lower speed with a lower latency. DDR3-1600 RAM that's rated at CAS7 should easily get CAS 6 or 5 at 1333 clock. Keep in mind to obtain those values you'll have to set them manually in the BIOS. Don't forget to set the command rate to 1T.