Need Advice for a "Win-Win" for my new Ram

[Rectifier]

I recently purchased 8 gigs of ripjaws (model: F3-12800CL9D-8GBRL , 2 sticks of 1600mhz).

Parts already in my build affected by this:

Gigabyte GA-890GPA-UD3H Motherboard
AMD Athlon II x4 645 "Propus" CPU
G.Skill F3-10666CL8-2GBHK Memory
^ 2 sticks of 1333mhz ram

Basically what I want to know is what the best configuration would be.
Ideally I would like to have both sets of ram for a total of 12 gigabytes.
I have done limited research, but it seems possible to overclock the 1333mhz ram to match the other two sticks, then set the multipliers so the cpu clock speed is unaffected. Or, just run the new sticks at 1333mhz, but at the 8-8-8-21 settings on the original sticks for more stability. Or I just have it all wrong. I'm not a stranger to using bios or anything like that; I built this computer, I just have ignorance towards this kind of situation.

In any case, I would really appreciate any solid info or advice.

[Tradesman]

You can try mixing the sets, but even mixing sets of the same exact model can be problematic, I think I'd try with them set to 1333 first, either the 8-8-8-21 you mentioned or 8-8-8-24 and if that can be made stable then try raising it from there (prob will also want to check CR (Command Rate or Command Timing) and have it at 2N or 2T (many AMD mobos default to to 1N or 1T if the use the T designator).

[Rectifier]

As soon as I read your post I went to go check the Bios defaults. Sure enough, they weren't the stock settings for my 1333 sticks.

Instead of the listed 8-8-8-21 2T for stock stability and performance, my ram was configured at 9-9-9-24 1T roughly giving a clock speed of 1340.

I definitely want the CR at 2N/2T because the performance increase from 2 to 1 is only something like ~3% while undermining stability.

I like your advice Tradesman, I'll put these sticks at 8-8-8-21-2N/24-2N, run prime95 and memtest, and go from there.

[Tradesman]

Let us know how it goes, will be around the rest of the weekend (who am I kidding, I check in a few times a day)

[Rectifier]

I should get the package somewhere between Mon-Wed, I'll bump the thread when I receive it.

[Tradesman]

We'll be here...

[Rectifier]

Alright I'm back and just installed the ram sticks this morning. The only complaint I have about the new 4 gig 12800 sticks is that compared to my older sticks, the uneven heatshield jutted out slightly above them and made installation a little uncomfortable due to the pressure needed to lock any ram stick into the clips. However, for builders or performance users, this is a non-issue, and the sticks look stylistically attractive added onto the fact that I am not afraid of touching a sensitive surface with the heat shield covering anything important. That extra confidence when dealing with component installation is very important so kudos to you guys.

Started up the computer right after installation; the older sticks I left in their original slots and placed the newer ones in the other two.
They are in this arrangement, the plus sign being the old stick and the tilde representing the newer stick: +~+~
This means a configurations of old in slots 1/3 and new in slots 2/4.

The post screen indicated a memory size of over 12000 megabytes. In the Bios I overrode the auto settings for Dram and set the mem clock to 1333mhz with timings 8-8-8-21 2N. I did not change any of the voltage settings. I saved the changes to my CMOS and rebooted. Post screen again confirms the memory, where I proceeded to log into windows 7. I have been running the system at a low use just to get this post onto the forums and test stability during boot and into a somewhat idle state before using prime95 or memtest.

Most important question, do I need to adjust the voltage before using prime95/memtest?

In GPU-Z, this information was spat back at me. Does the memory tab indicate the actual frequency and timings with the SPD tab showing the default settings for the sticks?

[Tradesman]

Yes, the memory tab shows what you are actually operating at, and with voltages, go ahead and start at 1.5, hopefully that will suffice, but if any issues, feel free to raise it to 1.55 to stabilize (perfectly safe) and can always fine tune up or down from there. Keep us informed of progress

[Rectifier]

Ran prime95 for over 1.5 hours using a torture test with these settings:
4 threads, min FFT 8, max FFT 4096, unchecked run FFTs in-place box, memory to use (in MB) 10000, time to run FFT size (in minutes) 15

Using a combination of rainmeter and hw monitor, my cpu was at 100% utilization during the test, and 10.9-11.0 gb of the 12gb ram were used during the test. Noticed nothing unusual, I have pretty good faith in G.Skill products despite the more recommended test length of 8 hours, but I have to use the computer today for college coursework anyway.

Here are the relevant min/max data from hw monitor.


Tomorrow I will change the DRAM bios and use prime95 to test the viability of the 1600 clock speed with 9-9-9-24 2N and 1.55 V. If these settings do not work stability-wise, then I might try to tweak the numbers a little or simply revert to the slower clock speed.

[Tradesman]

Let us know what happens, and if off a little, maybe we can get the settings tweaked (if needed)

[Rectifier]

Well, I gave oc'ing to 1600 the best I could, tried multiple settings changes, but I just couldn't beat the stability using 1333 clock speed. AKA, minutes of stability on 1600 that could be counted on one hand in prime95 compared to hours of 1333 with no signs of stopping. I tried more timing and voltage settings than I care to remember...

I might change the timings, because after the unstable 1600 settings I opted for a safer 9-9-9-24 for the 1333 clock speed instead of the 8-8-8-21 I used prior, something to do another day.

But I am not disappointed with the oc results! I am pleased with being able to own 12 gigabytes of ram on my system when just 5 years ago I considered 4 gigabytes to be over the top. I mean come on its nuts if you think about it!

Anyway, I believe that this thread has fulfilled its purpose, so I would like to first thank Tradesman for his astute and helpful comments, and of course G.Skill for making such awesome products.

[Tradesman]

Sorry we couldn't hit 1600, but glad it's running stable and your pleased, AMD is just often tough to work with, keep in touch

[Rectifier]

Yes that was the conclusion I came to in my research for finding builds similar to my own. Not much you can do when the architecture of the cpu, not the speed of it, limits the ram.

Regardless I was pleasantly surprised that sticks two different stock frequencies could work together; and I was more interested in increasing my capacity than going super fast, especially considering the diminishing returns in performance compared to the strain on your machine.

[Tradesman]

Again, just glad we got them going, more often than not you can't do it, Enjoy!