1600MHz CL9 RAM actually running at 1066MHz CL7 - voltage issue? [full details included]

[cfmdobbie]

Hello gurus, I need your help! Today I've noticed that my current RAM is running at wrong speed and CAS levels, and I don't understand why. Can anyone explain what's going on, and suggest how to fix it?

I believe my motherboard and RAM both support 1600 MHz at 9-9-9-24, but my BIOS is reporting 1066 MHz at 7-7-7-20. System is not overclocked. I believe most/all options in BIOS are default (mostly set to Auto). It's a system I built in late 2009, and it's quite possible it's had this issue from the start. Oops!

Hardware is:
- Intel Core i5-750 (2.66GHz)
- Gigabyte GA-P55-UD3 r1.0 [http://www.gigabyte.com/products/product-page.aspx?pid=3164]
- Corsair Dominator TW3X4G1600C9D (kit of 2x2GB, DDR3, 1600MHz, 9-9-9-24) [http://www.corsair.com/tw3x4g1600c9d.html]

Regarding voltage, Gigabyte say the motherboard has "4 x 1.5V DDR3 DIMM sockets". Corsair's production description says 1.65V, but also SPD Voltage = 1.5V and Tested voltage = 1.8V. The modules are printed with 1.8V.

Regarding speed, Gigabyte say "DDR3 2200/1600/1333/1066/800 MHz". Corsair's product description says 1600MHz, but also Speed Rating = PC3-12800 (1600MHz), SPD Speed = 1333MHz, and Tested Speed = 1600MHz.

Looking at the BIOS I can confirm that:
- Modules are in correct slots (1 and 3)
- BCLK is reported as 133 MHz (believe correct for Core i5-750)
- BCLK control is disabled (i.e. BCLK is automatically set)
- System Memory Multiplier is set to "Auto (8x)". (Manual options are 6, 8 or 10.)
- DRAM voltage is Auto, which is reported as 1.5V


Is it the voltage that's the issue? Corsair advertise these modules as 1600 MHz, but is that only achievable when you go above the default settings for voltage? From Corsair's information, I would read the "defaults" for this RAM are 1.5V and 1333 MHz, but I'm not even getting that.

I'm not great when it comes to hardware, but I'm guessing my options are:

- Bump System Memory Multiplier up to 10x and force RAM to run at 1333 MHz?
- Increase BCLK to 200 to get 1600 MHz (overclocking CPU at the same time)?
- Increase memory voltage (beyond what Gigabyte advertise) and see what happens?

Or is this RAM just fundamentally incompatible with my system, and I should just get a new set of modules?


Any advice or guidance greatly appreciated!

 

[Supahos]

Any memory you buy will run into the same issues, so returning it won't help. Its up to you to get them running at the speed you want. Honestly the 1.65v sticks that are 1600 make no sense to me, there is no need for that much voltage at that speed/timing. There are plenty of 1600 sticks with better timings that run jsut fine at 1.5v. I'm guessing they use inferior chips and just throw voltage at them to stablize them.

But as for the speed, You have to decide what to do I would at least restrap them to 10x and run them at 1333. as for the OC you have to decide on that one, if you make the strap 10x you'd only have to FSB oc to 160 in order to reach the rated speeds I belive so that might be the easiest solution for 1600 mhz. you could also drop main multi a bit to keep cpu speed teh same even with teh Bclock OC

 

[cfmdobbie]

So you think it's definitely a voltage issue then?

Does it make sense to you that the spec of the modules mentions 1.5V, yet they can't perform at the advertised speed on that voltage? Sorry if this is a silly or obvious question - I don't have a good grasp of how truthful/dishonest marketing is in the world of memory modules!

 

[Tradesman1]

The sticks are spec 1.65 at 1600, and while advertised as 'high performance', these are nothing more than bare basic entry level sticks, 1600/9 is considered entry level - at 1600 high performance is considered at a spec CL of 7 (even 8) - what you may want to do is check your BIOS and try enabling XMP and selecting Profile 1, if you have the latest BIOS it should thenm up for you at 1600, if not, give me a holler and we can do so manually

 

[cfmdobbie]

Very sorry for the delay in replying, had a bit of a crisis that got in the way of looking at this.

I bumped the System Memory Multiplier up to 10x and the system booted, but software kept crashing and the system blue-screened. Do I need to increase the voltage as well? Or at this point is there really no advice other than play with it and see what works?

I'm looking at a BIOS update - one of the changes listed is "Enhanced memory compatibility" so that might help.

More information later!

 

[cfmdobbie]

Okay, I've flashed the BIOS up to latest ("F9") and loaded optimized defaults. BIOS has definitely taken (new version appears on POST screen), RAM is still running at 1066 MHz.

On one screen in the BIOS it said "Clear CMOS to overcome wrong frequency issue" in the help text area, so I did a full CMOS clear and load optimized defaults. Still the same issue.

I cannot see any settings in the BIOS for XMP, although Gigabyte say this motherboard supports it.

--

So... I understand the restriction that with a BCLK of 133 MHz and a memory multiplier going up to 10x you can only hit 1333 MHz, never 1600 MHz. I would need to overclock the CPU to get the BCLK up to 160 before the memory could ever reach 1600 MHz. So the modules I bought are over-specced for this system - oh well.

I just don't understand why these modules are running at 1066 MHz, given that the SPD Speed is 1333 MHz. I am running them at 1.5V. I would like to think that the SPD Speed can be attained when running at SPD Voltage. These modules have an SPD Voltage of 1.5V, but the product description does say 1.65V... I wonder if the SPD Voltage is a typo?

So in the absence of XMP profiles, I guess I'll try tweaking multiplier and voltages and see how it goes.

 

[cfmdobbie]

Regarding XMP, the Gigabyte BIOS only displays the XMP settings if the modules support XMP. Corsair say these modules do, but the settings don't appear. Something's in error here, but I can't tell what, so nothing I can do about that.

Ran voltage up to 1.64V and monitored for a while, no heat or stability issues seen.

Additionally ran memory up to 1333 MHz (all other settings the same) and experienced crashes.

Then ran CAS up to 9-9-9-24 as well, and am monitoring. No issues yet. Will update later.

 

[Tradesman1]

If 1600 or better they should support XMP, however the info in the SPD profile (the XMP settings) is simply info, it's up to the BIOS to take that info and implement if correctly