Can't attain high RAM freq. Phenom II

[adelphia83]

I have a Phenom II 830 build that's been stable for months now. Until today I had a set of DDR3-1333 modules that I had midly overclocked to around 1500 or thereabouts. No issues but I had the chance to upgrade to DDR3-2133 modules, so I did.

Enter problems. Whenever I set the RAM ratio such that it brings the RAM speed to DDR3-1600 or beyond, I can't post. The BIOS just beeps and it proceeds to reset with defaults. I have turned down the speed of everything else (northbridge, CPU, HT, etc.) to eliminate variables, it's definitely the RAM speed that's giving me problems. I've also relaxed timings to their default which is 11-10-11-28. Still these will run nowhere near their rated speeds.

Is this an issue with the Phenom II architecture I have? When I bought it I think it advertised DDR3-1333 supported with higher speeds technically being an overclock. So maybe DDR3-1600+ just isn't in the cards for this processor and/or AMD 770 chipset? Or might the RAM be at fault? It's Mushkin Blackline DDR3-2133 1.5v 10-11-10-28 found on Newegg. Pulling my hair out with this, perhaps it's time to jump ship to Intel in my search for speed!

 

[RGone]

Is this an issue with the Phenom II architecture I have? = Since the P2 is designed and rated at DDR 1333, DDR 1600 can be a problem even on boards that give the DDR 1600 as an OC spec.

When I bought it I think it advertised DDR3-1333 supported with higher speeds technically being an overclock. = That DDR 1600 is technically an overclock of the ram is true. Since the memory controller is inside the CPU (IMC), the cpu itself could be a limiting factor. All cpus are not identical for sure.

So maybe DDR3-1600+ just isn't in the cards for this processor and/or AMD 770 chipset? = The 770 chipset is rather dated today. Gigabyte according to reviews made up the chipset combination to make up that board back in 2009 or so when I saw it reviewed. It maybe just dated.

Or might the RAM be at fault? = You might try testing the ram sticks one at a time in the primary slot for single sticks and see if one boots and the other not. I have seen a bad stick keep a board from booting at all but have only one bad stick of ram.

1. I went thru the NewEgg users reviews for that ram and across 4 pages there were only 3 users I could verify were using the ram on AMD boards. Two of the user reviews showed using the newer FX series processor which has an IMC rated for DDR 1866. The other cpu in use was a Thuban X6 1090T which has a better IMC than the P2's. This could be a very great factor in the ram not doing DDR 1600 on your motherboard.

2. I know the ram is rated at 1.5Volts but to adjust to 1.55V on the ram will surely not hurt it and might be just the kick-start needed to get it to work @ close to DDR 1600. While going thru the 'user reviews' at the EGG, I saw just a few that had to raise the ram voltage to 1.55V on the Intel boards which are far more likely to use DDR 2133 ram. Used 1.55V on the ram to get it stable even on Intel board.

3. You might also see if there is a voltage setting for CPU/NB listed in your bios. That voltage is normally around 1.15V or so depending on the cpu installed. Because that is related to the IMC it has served some well to up it to about 1.225V or 1.25V. Hanging in the AMD cpu section as I normally do, we have suggested such a voltage increase just in general as a 'help' to the ram. None that I have seen in nearly two years has experienced any negativity from that Voltage increase. If you have that setting then raising the voltage as suggested might get the ram to work closer to DDR 1600.

There are the couple of things I can think off the top of my head. Maybe they will give you some relief in your search. Since you never had any DDR 1600 rated ram in the board, it is hard to guess if 'your' board/cpu combination is even capable of using downclocked ram at DDR 1600.

Good luck to you sir. Hope you get the situation sorted or you have success with an Intel rig.

 

[Knufire]

+1. In short, the IMC on the Phenom IIs isn't very strong. It's only rated for 1333MHz, Few can get to 1600, but past that is even rarer.

Best bet is to try to tighten timings if you can't get freq higher.

 

[Darkside59]

I've haven't tried any rams above 1600mhz. Right now I have mine set of 4x4Gb Corsair Vengeance 1600Mhz @ 1600Mhz on 1.5v and its running smoothly. I was planning on getting a set of 2133Mhz dimm but luckily I found this page. I've never knew these PH2 IMC are limited. Do that include the Ph2 x4 975BE also? Cause I have my 975BE clocked to 4.1Ghz and it is very stable.



*Edit*
Without touching the BIOS, it automatically set the speed to stock @ 1333Mhz.

 

[Knufire]

Some are better than others, and yes that includes the 975 BE. The one PIIX4 that doesn't have a limited IMC is the 960T, as it's actually PIIX6 with two locked cores. The X6's had a better IMC on them.

Obviously it's chip dependent. I don't have as much experience with AMD overclocking as others, but 1600MHz RAM on a PII X4 isn't exceedingly rare, just not common either.