Help UNDERclocking RAM

[blueurmind85]

Hey everyone,

This is my first post here as well as being new to overclocking, so please bear with me.

I'm running:

MOBO: GA-890GPA-UD3H (rev 3.1)
CPU: AMD Phenom II x6 1055t
RAM: CML32GX3M4A1600C10B (CORSAIR Vengeance LP 32GB (4 x 8GB) DDR3 1600)

I recently upgraded to this RAM and am having a lot of difficulty underclocking it in order to overclock my CPU. I finally got the RAM stable with CPU at stock settings by dropping the multiplier down to run the RAM at 1066MHz with the timings set to "Auto" (SPD - 7/7/7/20/26 @ 1.5v). I just learned about single/dual/quad rank RAM from Corsair's website and they had a helpful little graph showing that my CPU cannot handle this configuration of RAM above 1066MHZ.

Here's the problem:

Before I upgraded, I was running 8GB (2 x 4GB) @ 1333MHz (9/9/9/24) and could get the CPU to overclock stabily to 3.5GHz (no voltage increase) by running the core clock at 250 and setting the RAM multiplier at x5.33 which put the RAM at 1332MHz. Now that I am dealing with this RAM that won't seem to cooperate at that speed, It seemed logical to drop the multiplier down to x4 which put the ram at 1000MHz. Every time I save the settings after trying (many, many) different timings, after restarting I just get a message saying that the system has experienced boot failure due to overclocking and that it has been reset. After a while I tried putting the CPU back to stock and running the RAM at 800MHz with timings set to "Auto" (which matched the corresponding SPD in CPU-Z) and the same thing happened.

Does anyone have any helpful insight? Am I just screwed because I can't run this RAM at any other speed than 1066MHz? Is there a feasible way that I might be able to under/overclock this RAM lower/higher than 1066MHz to accommodate overclocking the CPU? I've tried tweaking the voltages and that doesn't seem to help...and I don't feel I should have to to underclock the RAM especially because the SPD for 800MHz states the lower timings should work at 1.5v.

For what it's worth, my motherboard's revision does claim compatibility with AM3+ CPU's with the latest BIOS and I do intend to upgrade to a black edition FX processor at some point which looks like it will provide a much easier time with overclocking. If that's my only solution, than so be it!

Any input is greatly appreciated. Thanks!

 

[caddi daddi]

start out by pulling it back to 8 gigs of ram.
boot to bios and reset to default.
sometimes it can be a little work to get 16 gigs to work.

 

[Mandrake4565]

start out by pulling it back to 8 gigs of ram.
boot to bios and reset to default.
sometimes it can be a little work to get 16 gigs to work.

This and did you do a clear CMOS before putting the new sticks in? Additionally having 4x4g sticks will put more stress on the Cpu IMC and you may need to give the Dram a little more voltage as well as the Cpu Nb Vid.

Before I upgraded, I was running 8GB (2 x 4GB) @ 1333MHz (9/9/9/24) and could get the CPU to overclock stabily to 3.5GHz (no voltage increase) by running the core clock at 250 and setting the RAM multiplier at x5.33 which put the RAM at 1332MHz.

One note on this quote, when one leave the board on auto and overclocks. The board will, in most cases, give more voltage then stock to keep up with the demands of the chip. A lot of times, giving it more then it needs, it is best to set the voltage manually when overclocking.

 

[blueurmind85]

Thank you!

To clarify, the kit I upgraded to is 32GB (4 x 8GB) from an 8GB (2 x 4GB) kit. I'm not sure if that really makes a difference in the suggestion of pulling back to 8GB and resetting the settings/clearing the CMOS (which I did not do before installing the new RAM). I did at one point have to clear the CMOS because of certain settings that put me in a boot loop. I left the new 32GB RAM in when I cleared the CMOS. Would it still be necessary to scale back to 8GB by only putting one stick in and clearing the CMOS? Or should I put the old 8GB kit back in and clear the CMOS? Or was clearing the CMOS with the new kit in good enough?

If this helps, I'm happy to report that I ran Memtest86+ for 6 hours overnight with everything on stock/auto and RAM running at 1066MHz with no errors (I got 10 errors whlie running it for 3 hours at 1333MHz).

Regarding tweaking the voltages due to the higher capacity, since it seems the RAM is stable on "Auto" voltages running @ 1066MHz, would it still be necessary to up the voltages on the DRAM and NB Vid to underclock the RAM to 1000MHz while overclocking the RAM to 3500MHz?

 

[Mandrake4565]

If you passes 6 hours memtest it's most likely stable at 1066. If you're happy with it running there then you're good to go and do not need to touch the voltages or clear the CMOS. Especially since you had cleared it due to the boot loop with these sticks in. If you want to try and speed them up to 1333 Mhz then you'll will likely need to adjust the voltages to do so. Otherwise enjoy it and happy computing.

 

[blueurmind85]

If you passes 6 hours memtest it's most likely stable at 1066. If you're happy with it running there then you're good to go and do not need to touch the voltages or clear the CMOS. Especially since you had cleared it due to the boot loop with these sticks in. If you want to try and speed them up to 1333 Mhz then you'll will likely need to adjust the voltages to do so. Otherwise enjoy it and happy computing.

I'm still having a lot of trouble with this RAM. It is still stable at 1066MHz, but I CANNOT get it to underclock AT ALL. I'm trying to overclock the CPU to 3.5GHz by putting the core clock at 250. In order to keep the RAM at < 1066MHz I have to put the multiplier at x4 which puts the speed at 1000MHz. It simply will not run stable. I can't get it to run stable at 800MHz with everything else at stock. For the most part, I am happy with it running at 1066MHz, but I'd LIKE to be able to OC the CPU. I shouldn't have to adjust the voltages to underclock it, right? The SPD for 800MHz in CPU-Z is showing at 1.5v. I've set the other timings to match the SPD, but there are a lot of settings in the BIOS for the RAM timings that aren't available on the SPD or anywhere else for that matter. Would there be a logical reason why it is impossible to get this RAM to underclock lower than 1066MHz? Is it just a matter of messing with the timings enough to finally find the right combination (which seems like it could literally take forever)?

 

[Mandrake4565]

The amount of ram is likely the cause of you being unable to Oc the Cpu. Just so I'm clear, you can set the Ram to 800 Mhz but when you Oc the cpu it's not stable. For starters did you slowly try to push the Fsb up to 250 Mhz or just jump there? Overclocking takes patience to do correctly, you can't just jump to 3.5 Ghz and hope for the best, this will lead to a lot of frustration. Try setting the ram to 800 Mhz and then raise the Fsb 5 mhz test using prime blend for 20 minutes if it passes, raise it again, if it fails add some Cpu V to see if you can get it stable. At some point I will bet you're going to need to add some Cpu Nb Vid because of the amount of ram you're trying to run. Another option is take 1 set of sticks out and try overclocking once you get to a stable Oc, put the second set back in. If you then have issues you know it's the ram causing it.

 

[blueurmind85]

Just so I'm clear, you can set the Ram to 800 Mhz but when you Oc the cpu it's not stable.

No, I can't underclock the RAM at all...in fact I can't get it to run stable at anything except 1066MHz. I want to get the RAM stable at 800MHz without trying to OC the CPU so I can then OC the CPU and not push the RAM past 1066MHz.

For starters did you slowly try to push the Fsb up to 250 Mhz or just jump there?

I did just jump there because that's what I was able to get it stable at with my last 8GB (4GB x 2) RAM configuration. I realize now that you point that out that it was a mistake to assume that I could load four times the amount of RAM into the motherboard and expect the processor to run the same way as it did before. I guess I didn't realize how much the RAM configuration impacts the function of the CPU. Lesson learned.

That being said, I feel like it should not be so hard to get the RAM to run at 800MHz. I feel like I should be able to just leave everything else on stock/Auto (including the RAM timings which adjust automatically with the clock and how I got it stable at 1066MHz) and drop the multiplier and have it be stable. Obviously that is not the case here unfortunately, so I'm really having a hard time understanding what I need to do to get this RAM underclocked.

 

[Mr.Scott]

How about some CPUz pics.
When you say "1066" that says to me ram at 2133. We all need to get on the same page here.

 

[blueurmind85]

How about some CPUz pics.
When you say "1066" that says to me ram at 2133. We all need to get on the same page here.

When I say "1066MHz," I mean: core clock (200) x multiplier (5.33) = 1066MHz. When I say "800MHz" I mean: core clock (200) x multiplier (4) = 800MHz. Is that not how I should describe the speed I am trying to run my RAM at?

I will post some CPU-Z pics tonight (I'm not currently using that PC). I mean I've noticed that the profile for the RAM in CPU-Z is half of what the end result of "core clock x multiplier = speed" is. The RAM is CORSAIR Vengeance LP 32GB (4 x 8GB) DDR3 1600 (PC3 12800) if that helps for now.

 

[Mr.Scott]

I mean I've noticed that the profile for the RAM in CPU-Z is half of what the end result of "core clock x multiplier = speed" is.

This answered my question.
We are on the same plane.
Now my 2 cents:
The is no reason on Earth that even with 32 gig of ram you cannot run at the stock speed (1600) and timings @ the stock voltage.
Send that s**t back.
You're not underclocking anything. You are running a divider to keep the ram speed in check while you overclock the FSB.

 

[blueurmind85]

The is no reason on Earth that even with 32 gig of ram you cannot run at the stock speed (1600) and timings @ the stock voltage.

That's what I had assumed as well; however, while I was on Corsair's support page for my particular kit:

http://www.corsair.com/en-us/vengea...l-channel-ddr3-memory-kit-cml32gx3m4a1600c10b

there is a section under the "Support & FAQ" tab titled, "Corsair Memory Compatibility with AMD Platform." Under this category, there is a graph advising of the maximum speed certain AMD processor's are able to run RAM given the specific configuration as well as whether or not the RAM is single or dual rank. This is the first time I had ever seen a mention of single vs. dual rank memory and, upon further research, learned that any stick of RAM over 4GB is at least dual rank. According to the graph, Phenom II processor's are only capable of running four sticks of dual rank memory at a maximum of 1066MHZ. That is when I dropped the RAM multiplier to match that speed and poof...the RAM was stable. I had been trying persistently to get it stable at 1333MHz and just couldn't do it. There is a disclaimer under the graph that says, "Depending on your selected motherboard and memroy, the published speeds and configurations above may be exceeded, which will result in running your AMD processor outside of AMD published specifications." However, it doesn't say anywhere that I shouldn't be able to run the memory LOWER than the published specifications.

That being said, my question still remains:

How do I get this RAM to underclock below 1066MHz? I'm fine not running it any faster than 1066MHz for now, but I would like to run the CPU faster than the stock 2.8GHz. In order to do that, I HAVE to be able to underclock the RAM. I feel like the trouble I am having with this would be more understandable if I was trying to overclock the RAM. The only thing I can tell that might be causing the issue is:

When the timings are set to "Auto" with the multiplier set at x4 (to run the RAM at 800MHz), they are reflecting different values for the "Minimum RAS Active Time (15T)" and the "Row Cycle Time (20T)." In CPU-Z, those values are labeled as "17T" and "22T" respectively. When the "Auto" timings didn't work, the obvious solution was to adjust the timings manually to their appropriate values as called for in the SPD profile listed in CPU-Z. However, when I do that, there is a value listed for two settings "Trfc0 for DIMM1, DIMM3" and "Trfc1 for DIMM2, DIMM4." The "Auto" value lists those settings set at 260ns which is the listed value called for in the SPD profile displayed in the BIOS next to the "Auto" values. When I select to adjust the timings manually, those values are set at 350ns. My only options to choose from are 350ns, 300ns, 160ns, 110ns, and 90ns. There is no 260ns to select. I have tried 350ns, 300ns, and 160ns and none of them work. I did try the 350ns while the RAM multiplier was on x5.33 to run the RAM at 1066MHz and everything else matched the "Auto" timings. This worked fine, so it leads me to believe this is not the culprit while attempting to underclock the RAM further than 1066MHz. Regardless, I sure as f*** don't know what the culprit is.