AMD CPU + G.Skill DDR3-1600

[Alteris]

Ok I just installed the Ares set again and set the timings to the following.

8-8-8-24-2T-40-12-5-6-6-20 @ v1.50 @ 1600Mhz. Duel Channel Mode, Ganged

Will be doing my usual daily activities until a bsod occurs, Hopefully I don't get any and I can finally call it good and stable :/.

[Tradesman]

Keep us updated, we'll be waiting to hear

[TRS-80]

GA-MA790GPT-UD3H with AMD Phenom II BE 555 3.2 GHz dual core

Hai Guise!

I have been shopping around and doing research on getting memory for my "new" build, and it appears as though G.Skill is currently the leader insofar as "bang for your buck", particularly in the enthusiast segment. I am really looking forward to ordering some of your product and putting my "new" rig together.

The reason I say "new" is because I bought the mobo and CPU (and most of the other parts) like 2 years ago. However, due to responsibilities/work/life/etc. all my parts have been languishing here at my office gathering dust. Well, today I decided to pull them out, dust off the boxes, and continue my research where I had left off... choosing memory.

I have been reading up now about memory for more hours today than I care to admit to, and my head is starting to hurt. lol I was glad to find your forums, and have recently been reading up on some the issues with the AMD chipsets, memory controllers, etc. particularly in regards to the DDR3-1600 modules. So, my question is this:

Based on the following:
Mobo: Gigabyte GA-MA790GPT-UD3H
CPU: AMD Phenom II BE 555 3.2 GHz dual core*

...which of the following would I be better off with?:
G.SKILL Ripjaws Series 8GB (2 x 4GB) DDR3 1333 (PC3 10666) F3-10666CL7D-8GBRH, or
G.SKILL Ripjaws X Series 8GB (2 x 4GB) DDR3 1600 (PC3 12800) F3-12800CL8D-8GBXM

* I also hope to be able to unlock a 3rd or 4th core in this CPU, in effect possibly turning it into a 955. I will have no way of knowing thay however until I fire it up, which will require memory modules.

If my calculations and research are correct, the 1600s might only offer slightly improved performance (due to increased clock speed but offset by higher latency, amirite?). But I have read of some problems with the 1600s not working at the advertised speed, particularly with certain AMD CPUs (x55s in particular). Please enlighten me if I have missed something, or advise me on which ones I should go with.

Also, I had a second question, this mobo supports up to 16 GB of system memory in 4 slots. I plan to maybe add another 8 GB later, but have read of problems with the AMD controllers and using all 4 slots. Should I just be happy to have 8 GB of memory and call it a day?

[Tradesman]

The 965 Rev C3 was the first AMD that could be fairly reliable about running 1600, that line of CPUs is actually rated up to 1333, see AMD freq guide below

http://support.amd.com/us/kbarticles...encyguide.aspx

so I'd look at both the 1333 and 1600, if you go 1600 and they can't run at that, can always downclock to 1333......and in the event you upgrade the CPU to something that can handle 1600 or better then you'll have 1600 sticks. The Ripjaws X set you have picked out would be a good choice as would the Ares F3-1600C8D-8GAB. I think my first choice though would be the Snipers ( F3-12800CL9D-8GBSR)..these may be the best bet for running your 955 at 1600, unclock nicely and also overclock easily - they always seem to be a good fit with AMD systems

[TRS-80]

By all means, please correct me if I am wrong, but I thought that all other things being equal, lower latency was better? Or is it a matter of the 555/955 not being able to "handle" the lower/tighter latencies in a stable fashion?

The DIMMs I mentioned above have really low latencies (which I thought was good):
1333 Timing 7-7-7-21, Cas Latency 7, Voltage 1.5V
1600 Timing 8-8-8-24, Cas Latency 8, Voltage 1.5V

Compared to those Snipers you mentioned:
1600 Timing 9-9-9-24, Cas Latency 9, Voltage 1.5V

So, what am I missing here? I am not trying to be smart, I want to be enlightened.

All are currently within a few dollars of one another on NewEgg, so I just want to get the best bang (while being stable) for the buck.

If it is a limitation of the 555/955 CPU, I may get the 1600s with the tighter latencies (the Ripjaws X), see what I can get out of them, worst case downclock them for now as you suggested, with the idea of installing a better CPU later (maybe now sooner, lol), and then I should be able to get the full speed and tight latencies out of them. That was one of the main reasons I went with the socket AM3 architecture mobo, because of (what would have been) "future" (now current, lol) upgrade path. Then I could repurpose the 555/955 into a file server, HTPC, etc.

So, just to clarify, you were recommending the Snipers for my best shot at getting 1600 speed out of my 555/955 CPU, correct (and in order to do so, would need to "loosen" the timings)? Am I following along correctly?

[Tradesman]

Lower latency is better, but I'm trying to be realistic, the AMD CPUs are not known for a having a strong MCand when your CPU came out, with 1333 (it's rated freq) the norm was CL9 and some CL8 which equates to a CL9/CL10 1600 set of DRAM, so in actuality with your CPUthe 1600/8 set you chose might be able to run at 1600/9 or dropping to 1333 then maybe CL8 (which is the stock at 1600). I'd like the RJ or the Ares with your combo as you are sort of future-proofing for a different CPU (which is something I always try and do, that being going with the fastest and most DRAM I can with whats in the budget), but I also want you to know up front that they may not run at full freq/low CL....what I see all to often is people primarily looking at the mobo specs and thinking "Hey this will run 1866, 2133, et all and expect any DRAM they buy will run at true specs....and it's just not true, even with Intel, but in particular with AMD....i.e. if you look at your mobo QVL on DRAM you might see up to 1866 listed, the problem being, the mobo manufacturers 'test' DRAM at the mobo default (and yours is prob 1333 and may wwell have been 1066 when it was released

[TRS-80]

Yes, I'm pretty sure that the mobo default was/is 1333; 1600 was only listed as an "overclockable" setting:

http://www.gigabyte.com/products/pro...px?pid=3143#sp

I have been continuing to read while awaiting your replies. I have seen you post this link a few times (about the limitations of memory speeds in relation to certain AMD architectures):

http://support.amd.com/us/kbarticles...encyguide.aspx

I had a question, which of these memory modules we have been discussing are single vs. dual rank? This relates back to my second original question, about the possibility of populating the other 2 slots later. I plan on putting in 2x4GB for 8GB of memory now, and thought about possibly adding another 2x4GB later, for a total of 16MB. Because, according to that chart, if any of these modules we have been discussing are dual rank, then the limits of the Phenom II architecture would limit the speeds down to 1066 when I go to populate that 3rd and 4th slot.

I also believe in "future proofing" as much as possible. My plan was originally to eventually upgrade the CPU, and/or add memory, for a few dollars here and there, to increase performance until I just couldn't get any more out of this architecture, and then replace (actually probably repurpose) the mobo/cpu/ram if not build a whole new computer. So if I get some memory that is a little more than my current CPU can handle, but for around the same price, but can have it's full potential unleashed by a future CPU upgrade, I would be completely fine with that.

[Tradesman]

Am heading out for a bit, will be back in a couple hours or so

[Tradesman]

To start ranking is AMDs way of looking at how a user uses their DRAM as opposed as a characteristic of an individual or set of sticks, in effect it's similar to what Intel calls channeling as in Dual, Tri or Quad-channel where you take multiple sticks and have them run as one stick more or less. A single stick of DRAM or DRAM in single channel runs at 64 bit, 2 or Dual at 128, etc....AMD probably likes calling it 'ranks' as they have no CPUs capable of Tri or Quad channel. Single rank or channel (say with 2 sticks, in the most basic terms) allows one stick with an application and the other to run with a second app or possible to be 'assigned' to a core or set of cores) whereas dual rank/channel allows all the DRAM to run as a single entity and go wherever needed as needed...In todays world with multiple cores and more folks multitasking the norm is towards dual, however there are still instances and users that show a gain from single rank/channel. All DRAM basically is capable of running in either mode. As I've mentioned previously the MC (memory controllers) in AMD CPUs isn't as strong overall as Intel's so while it may just be niche the want to occupy it can be problematic in setting up DRAM on AMD as opposed to Intel....

Hope this helps, be happy to try and expound on this if needed.

[TRS-80]

My sole concern regarding "rank" is as it pertains to adding a third and fourth DIMM later on. In the AMD article linked above (DDR3 Memory Frequency Guide) the chart states that populating 4/4 slots with "single rank" memory will allow speeds up to 1333 with my current Phenom II architecture, but up to 1600 if I later upgrade to an FX processor, but only if it is "single rank" memory. Further down the page, under the "Memory Modules" heading, 1.d.ii. it says "Most memory should be clearly identified if it is dual rank memory and if not identified, it is usually single rank memory." So I guess I should just stop worrying, as apparently most memory is "single rank"?

I think I am going to pull the trigger and order some memory today. I am tired of doing research, time to get this baby fired up.

Thanks Tradesman for all your responses and help. I am now one step closer to getting my gaming rig back up and running.

[Tradesman]

Let us know what you get, and as always, if any problems we're here

[TRS-80]

Alright, I thought I was done but not quite.

It turns out there is not much upgrade path, CPU wise, for me with this socket AM3 mobo. I can basically upgrade to a 4 or 6 core Phenom II, but that's about it. It turns out the FX series processors are all AM3+ based sockets, and it doesn't look like Gigabyte will be supporting them through a BIOS update on my mobo. So, so much for the theory of future proofing (and buying memory with that in mind; although, I'm sure I could still probably re-use some DDR3-1600 in a new CPU/mobo swapout, or another build, later...).

But the thought crossed my mind, should I just get some 1333, as recommended by AMD in this chart (I have a Phenom II CPU)?:
http://support.amd.com/us/kbarticles...uide.aspx#NOTE

OTOH, my mobo says it supports up to 1600 speed memory (when overclocked):
http://www.gigabyte.com/products/pro...px?pid=3143#sp

In fact, Gigabyte lists G.Skill F3-12800CL9D-4GBNQ as approved modules at 1600 (but CL 9):
http://download.gigabyte.us/FileList...90gpt-ud3h.pdf

Honestly, there is not much price difference between the 1333 and the 1600 at this time. I just want to squeeze out the most performance possible, while of course remaining stable.

And searching this site with my specific mobo model yields a mixed bag, with some people able to get various modules running at 1600, and some not, in which case they run them at reduced 1333 settings.

Do you think I am being unrealistic thinking I may get something like these Ares (F3-1600C8D-8GAB) to run at their advertised settings (Timing 8-8-8, Cas Latency 8, Voltage 1.5V)?
http://www.newegg.com/Product/Produc...tem=20-231-548

However, maybe that is asking too much out of the memory controller in my Phenom II Black Edition 555 CPU? In which case, maybe I should settle on some 1600s rated at a little looser timings (F3-1600C9D-8GAB) (Timing 9-9-9, Cas Latency 9, Voltage 1.5V) in order to not disappoint myself?
http://www.newegg.com/Product/Produc...tem=20-231-546

Sorry so many questions guys, this memory thing has really got me stumped, and honestly was probably the reason the project got shelved in the first place. I have learned a lot more about memory since then, but still not 100% sure what to do. I would really like to pull the trigger on one of those Ares, if you think they will work at the advertised timings. I am also open to other suggestions.

[Tradesman]

I'd say go for it, you might get them to run to spec, of possibly at CL9, if not can drop to 1333, and with the tighter CL8, if you go to a new rig these should be able to run 1866 @CL9, possibly 2133/CL10 (though that would prob require an Intel CPU, if you go that route)

[TRS-80]

Yeah, since they are really all around the same price anyway, even if they don't work at 1600, what am I really losing anyway? They might work, and if not, I will run them at 1333, and I can probably re-purpose them in something else later anyway at the tighter timings. Maybe even in an Intel?

I have always been an AMD guy, but man, this entire business of unstable memory controllers has been extremely disturbing to me. I may have to consider Intel in my next build.

Well, I am really looking forward to getting some memory here and firing this sucker up and seeing if I won the "extra core lottery" (a lot of those 555s were perfectly good 955s that they sold as 555s to keep up with demand; I had read at time of purchase fairly high success rates in turning on the other 2 cores).

As another side note, I believe that my 555 is a C3 revision (I think they all were), which means that it may not be plagued by some of the memory controller issues I have been reading about. So wish me luck.

Well TMan, I thank you again for your input. I am getting pretty tired after being on the computer reading for the better part of 2 days, so I am going to go home and rest. After sleeping on this for a few days, I will order some memory, but not before checking back here first. If anyone else has anything to add, please feel free to chime in.

[Tradesman]

We'll be looking for you