i7 920 and Memory - How much trouble am I in??

[Natalia]

So, I just swapped out my old Motherboard and CPU for a i7 920 and the ASUS P6T6 Motherboard. I kept my OCZ DDR3 that I used to use - but when I was reading though the Motherboard manual just now - I saw a big warning that I should be using low voltage memory.

Right now I have RAM rated to run at 2.1V - which is over the 1.9V it says I should be using, and says also that I might permanentally damange my CPU.

So, I rushed to Newegg and order some new RAM:
http://www.newegg.com/Product/Produc...82E16820227365


But between now and when I get it - am I going to damage my Motherboard / CPU???

Right now I have the RAM voltage to Auto - and I can't find any program that will tell me what Auto is setting it to -not CPUz, not SpeedFan, not HardwareMonitor.


Should I not use my computer until the new memory arrives? Or will I be safe as long as I don't overclock a thing?

[funk32]

So, I just swapped out my old Motherboard and CPU for a i7 920 and the ASUS P6T6 Motherboard. I kept my OCZ DDR3 that I used to use - but when I was reading though the Motherboard manual just now - I saw a big warning that I should be using low voltage memory.

Right now I have RAM rated to run at 2.1V - which is over the 1.9V it says I should be using, and says also that I might permanentally damange my CPU.

So, I rushed to Newegg and order some new RAM:
http://www.newegg.com/Product/Produc...82E16820227365


But between now and when I get it - am I going to damage my Motherboard / CPU???

Right now I have the RAM voltage to Auto - and I can't find any program that will tell me what Auto is setting it to -not CPUz, not SpeedFan, not HardwareMonitor.


Should I not use my computer until the new memory arrives? Or will I be safe as long as I don't overclock a thing?

im sure the max intel says is 1.65V not 1.9 at least thats what comes up when i went higher to see if i could get alittle more. but didnt get enough to be worth it

[Natalia]

So - does that mean I am in trouble or no?

-- So confused....

[jcniest5]

Memory for anything earlier than X58 goes all the way to 2.1V (some even more). It's a hit and miss when using memory rated for high voltage on low voltage system. Awhile back, I used my Corsair DDR3 1.7v memory on my Asus Rampage II Extreme (2x1GB kit) and it worked fine. You won't know if it will work until you actually try it. The older memory kit will only give you dual-channel, however since they only come in two sticks kit (unlike three-sticks kit for X58 DDR3 system). Try and you will know and go from there.

[cky2k6]

yes, I would say you're in pretty deep trouble, especially what your vtt is set to currently. If auto set ram to over 2v, and your vtt is low, you are very quickly going to kill your chip. vtt must be within .5v of ram voltage, so with 2.1v stock, vtt should be 1.65v to accomodate any vdroop. Your ram has spd settings you can check in cpu-z, and these settings have various speeds, timings and voltatges. Find out the speed at which your ram can run at around 1.8v, and manually enter it into the bios, and set your vtt to at least 1.35v, and you'll be fine.

[Zucker2k]

yes, I would say you're in pretty deep trouble, especially what your vtt is set to currently. If auto set ram to over 2v, and your vtt is low, you are very quickly going to kill your chip. vtt must be within .5v of ram voltage, so with 2.1v stock, vtt should be 1.65v to accomodate any vdroop. Your ram has spd settings you can check in cpu-z, and these settings have various speeds, timings and voltatges. Find out the speed at which your ram can run at around 1.8v, and manually enter it into the bios, and set your vtt to at least 1.35v, and you'll be fine.

He's exactly right.

What you need to do is to clock down your ram so that you can feed it less volts (undervolt).

I would pick a low ram divider = DDR3 1066 (if available should be the sweet spot)

Give it the lowest volts it needs to run stable (Maybe 1.65, at most at default CAS latency and timings)

Remember, you want to maintain a .5v difference between vdimm and vtt, so 1.65v means you could run vtt as low as 1.15v.

To be safe, I'd set 1.3v vtt (this will allow you to overclock past 4Ghz), allowing you to push vdimm all the way to 1.75v (a .45 difference, which also makes room for overvolting on your mobo).

Be sure to set everything manually! Trust nothing to AUTO. Goodluck.

[Natalia]

The vtt is the "DRAM/QPI Voltage" right?


And in CPU-z - it shows 4 sets of memory timings and at the bottom it says 1.5V for each of them - does that mean the BIOS is choosing that value?

[Natalia]

Here's what CPUz says:




Does that mean my stuff is running at 1.5V??

[SoulsCollective]

No. SPD is not what the RAM is actually running at, it's the automatic timings programmed in that are then read by your BIOS to help determine the timings, voltage, etc. You need to actually go into BIOS and see what RAM voltage is set to.

[003]

Make sure that vDimm - vQPI ≤ 0.5v and you should be fine.

[eva2000]

So, I just swapped out my old Motherboard and CPU for a i7 920 and the ASUS P6T6 Motherboard. I kept my OCZ DDR3 that I used to use - but when I was reading though the Motherboard manual just now - I saw a big warning that I should be using low voltage memory.

Right now I have RAM rated to run at 2.1V - which is over the 1.9V it says I should be using, and says also that I might permanentally damange my CPU.

So, I rushed to Newegg and order some new RAM:
http://www.newegg.com/Product/Produc...82E16820227365


But between now and when I get it - am I going to damage my Motherboard / CPU???

Right now I have the RAM voltage to Auto - and I can't find any program that will tell me what Auto is setting it to -not CPUz, not SpeedFan, not HardwareMonitor.


Should I not use my computer until the new memory arrives? Or will I be safe as long as I don't overclock a thing?

That statement in Asus manual has long been overturned by Bit-tech's article and Anandtech.com article and info they received from intel themselves read http://i4memory.com/wp/article/327 and http://i4memory.com/wp/article/191

The correct statement should be

"Vdimm >1.65v is safe as long as vdimm is within 0.5v of uncore voltage"

DFI CPU VTT = Uncore volts
Asus QPI/DRAM = Uncore volts

Default DFI CPU VTT = 1.21v which i think is similar to Asus ?? So now you know why Asus put >1.65v vdimm warning label there. As folks who aren't aware of the uncore to vdimm 0.5v requirement, will try to keep CPU VTT at default values and raise vdimm beyond 1.65v. This will cause vdimm to uncore voltage to move out of bounds from 0.5v requirement and thus cause damage to CPU.

To keep CPU safe, VDIMM must keep to 0.5v within Uncore. DFI UT X58-T3EH8 bios does this automatically for you - see point #16 for DRAM Safety for my DFI thread at http://i4memory.com/102537-post3.html

Max intel spec'd uncore/CPU VTT is 1.35v and default uncore is 1.1v (but most X58 boards set 1.2v) so basically you have vdimm range of 1.6-1.85v vdimm to be comfortable within CPU safe parameters.

But folks are benching CPU VTT/Uncore to 1.5-1.6v to get >DDR3-1866 speeds. For example Corsair DDR3-1866 modules are validated at CPU VTT /uncore of 1.5+v.

Now to be 100% safe, measure your vdimm and uncore volts using multimeter for your board so you can precisely know the distance between vdimm and uncore volts.

For DFI UT X58-T3EH8 i did those measurements at http://i4memory.com/f80/dfi-ut-x58-t...results-14011/ using DFI's provided DMM measure pads



Right now testing Asus P6T6 WS Revolution as well but monitoring in bios and windows don't report cpu vtt so hard to get an exact value but so far so good http://i4memory.com/showthread.php?t=18752

Older DDR3 with higher rated voltages will work just to keep within 1.65v vdimm, you'd probably have to underclock memory or loosen timings.

[donmarkoni]

You can see your vdimm in bios and in windows use Everest to read vdimm if you're not familiar with using multimeter.