DDR3 Corsair memory not operating at correct speed

[tha_vice]

So I have this Memory and this board.

CORSAIR Vengeance 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model CMZ8GX3M2A1600C9B


GIGABYTE GA-990FXA-UD3 AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Motherboard


My issue is that The advertised stock speed of these pair of moduels says DDR3 1600, every time I post, get into windows and check Cpu-z it says otherwise * 1333mhz* or 667mhzx2, but here's the part I don't understand.

I did a lot of research prior to buying the memory - it's on the supported list, and the vengance series has received a lot of good reviews - hence my reason for even buying it that and it was cheap. Aparently i'm missing something here, because the Bios completely contradicts what the Post, and Cpu-z are telling me - via SPD and manual settings , it's showing the memory at 1600 mhz , with the correct timings from the Jdec, and corsairs timings table - voltage included. 1.5V

What I'm at a loss for is shouldn't this board just auto detect this memmory and be humming along at 1600? I'll never rule out the possiblity that I've done something wrong, but I've been building systems for years; admitidely I am new to the AMD/gigabyte platform, but nothing I'm doing just yet really calls for O.C'ing or extreme tweaking. right now i'm just making sure I don't need to RMA pos hardware.

Please help >_<

 

[jaquith]

Welcome to Tom's Forum!

By Default the RAM is going to run @ DDR3-1333 'SPD', you must adjust the DRAM Multiplier or DRAM Frequency to the RAM's Rated Frequency, and then also adjust both the CAS Timings and DRAM Voltage according to spec.

Next depending on the CPU you 'may' need to OC, in the case of AMD the FX can run up to DDR3-1866 with little effort, but other AMD CPU's need more complex settings and adjustments so the CPU's IMC doesn't 'dropout' and cause errors.

The FX reads 'SPD' data and not XMP data so by default it will run up to the highest 'SPD' encoded data not to exceed DDR3-1866 and not the XMP (Intel only) encoded data on the RAM.

Some non-FX and non-Phenom simply 'shouldn't' run faster than DDR3-1333 due to IMC limitations.

Q - What EXACT CPU?

 

[tha_vice]

FX-8120

 

[jaquith]

To run DDR3-1600 9-9-9-24-2N (2, 2N & 2T are the same) @ 1.50v

BIOS:
Set Memory Clock -> 8 ; 8*200Mhz = 1600MHz
DRAM Configuration /Enter
DDR3 Timing Items -> Manual

1T/2T Command Timing -> 2T
CAS# latency -> 9
RAS to CAS R/W Delay -> 9
Row Precharge Time -> 9
Minimum RAS Active Time -> 24

DRAM Voltage Control -> 1.50v (one set); 1.55v (2 sets)

Save & Exit = Yes

1. Verify with CPU-z 'Memory' tab ; DRAM Frequency = 800MHz (DDR3 = Double Data Rate rev 3,so 800MHz*2= 1600MHz)
2. Create a bootable CD/DVD of Memtest86+ using the ISO/zip file, boot, and test for a minimum of 4-passes. Memtest86+ - http://www.memtest.org/

Good Luck!

 

[tha_vice]

Thanks for your help, I will try this once I get home and let you know the results!

 

[tha_vice]

Ok so the memory reports at the correct clock, but the timings aren't anywhere near 9 9 9 24 in CPU-ID.

I'll send a screenshot later tonight.

But good news is that I'm getting what I paid for - 1600mhz ram, slight more because i've bumped the FSB up a few notches. I also notice the the post fails hardcore when I turn up the multipliers to 9.xx for 1866... any thoughts ?

 

[jaquith]

The CMZ8GX3M2A1600C9B is Rated DDR3-1600 9-9-9-24-2N @ 1.50v - http://www.corsair.com/us/vengeance-8gb-dual-channel-ddr3-memory-kit-cmz8gx3m2a1600c9b.html

IF you set the RAM manually as I posted then it 'is' running @ Rated.

Overclocking RAM is hit & miss, and especially more difficult with (2) TWO Sets. Further, the Corsair Vengeance are not 'ideal' candidates to OC above Rated Frequency and CAS.

Possible OC's:

Frequency & CAS OC:
BIOS:
Set Memory Clock -> 9.33 ; 9.33*200Mhz = 1866MHz
DRAM Configuration /Enter
DDR3 Timing Items -> Manual

1T/2T Command Timing -> 2T
CAS# latency -> 9
RAS to CAS R/W Delay -> 9
Row Precharge Time -> 9
Minimum RAS Active Time -> 24

DRAM Voltage Control -> 1.55v~1.60v (one set); 1.60v~1.65v (2 sets)
CPU NB VID Control -> +0.075 ; ONLY if needed ; never exceed +0.175 or 1.35v

Save & Exit = Yes

Frequency:
BIOS:
Set Memory Clock -> 9.33 ; 9.33*200Mhz = 1866MHz
DRAM Configuration /Enter
DDR3 Timing Items -> Manual

1T/2T Command Timing -> 2T
CAS# latency -> 10
RAS to CAS R/W Delay -> 10
Row Precharge Time -> 10
Minimum RAS Active Time -> 30

DRAM Voltage Control -> 1.55v~1.60v (one set); 1.60v~1.65v (2 sets)
CPU NB VID Control -> +0.075 ; ONLY if needed ; never exceed +0.175 or 1.35v

Save & Exit = Yes

 

[tha_vice]

Somewhat lost on the terminology " one set", and " 2 sets". If it's complicated i'll research, if not maybe you can explain while i've got my mind on this.

 

[jaquith]

(1) set of CMZ8GX3M2A1600C9B = 8GB
(2) sets of CMZ8GX3M2A1600C9B = 16GB

I know what RAM you have, but not how many kits (sets).

 

[tha_vice]

Ah, it's 2x 4GB

 

[jaquith]

Cool, I was simply covering my bases for you. Let me know how she turns-out, and Good Luck!

 

[tha_vice]

thanks man!

 

[tha_vice]

Uploaded with ImageShack.us

What I got so far, and this is what I was talking about with the wierd timings.

 

[tha_vice]

Oc'd and ready to rock

 

[jaquith]

CPU-z at least for the RAM is totally wrong, and whatever you have set in the BIOS rules. You can also try AIDA64 Extreme http://www.aida64.com/downloads

 

[tha_vice]

Best answer selected by tha_vice.

 

[tha_vice]

Thanks again, I'll proabbly open another post about cooling this rig, as I wanna push to the 5ghz range on this Fx-8120, and possibly better ram for Oc'ing.

 

[nikorr]

This topic has been closed by Nikorr