1333 MHz at 1.5 volts or 1600 MHz at 1.65 volts?

[TheAvenger7]

I have two Kingston HyperX 4GB sticks running in dual channel at 8GB and at 1.65 volts in order to attain 1600 MHz.

However, I read that running RAM at that voltage with an Ivy Bridge CPU as its memory controller can officially support 5% higher or lower than 1.5 volts and it may be detrimental in the long run.

Should I undervolt and run it at 1.5 volts and 1333 MHz? Also, will I notice a drop in performance? It has been a month since I've built my computer and haven't noticed any irregularities running RAM at 1.65 volts.

Thanks in advance.

 

[jimmybgood9]

I doubt if you'll notice the difference, though you might be able to find a synthetic benchmark that will show a small memory subsystem performance gain. I wouldn't bother.

If you want to overclock, do it systematically. Can you boost the voltage in 0.05v units? Will the RAM run at 1600 at 1.55 or 1.60? Even passing memtest is not assurance that the your system is stable. Heavy processor, storage, video and peripheral use can trigger "issues" that weren't uncovered with memory tests running alone.

 

[know of fence]

Why are those modules labelled 1.65 V, they seem to run fine at 1.5 V and 1600 MHz?

After some testing with Kingston HyperX 4GB (Genesis KHX1600C9D3/4G), I got different Latencies (9-11-11-29) instead of (9-9-9-24); and 14% increase in memory Bandwidth, just looking at memtest86+ numbers and changing the clock from 1333 to 1600 MHz.

Intresting to note that between Clarkdale and Ivy Bridge memory bandwidth doubled even when tested with the same DIMMs and 1333 MHz, from 9 GB/s to 17 GB/s.

 

[LOL_Wut_Axel]

You can run that RAM at 1.60V/1600MHz, which would be fine for Ivy/Sandy Bridge.

 

[blastingcap]

Except for APUs, 1333 is fine for most games and most programs in general. If I were you, I'd save the wear and tear on the memory controller and go 1.5v. I suppose if you're using the iGPU for gaming, then faster RAM is warranted.

http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3

 

[TheAvenger7]

Except for APUs, 1333 is fine for most games and most programs in general. If I were you, I'd save the wear and tear on the memory controller and go 1.5v. I suppose if you're using the iGPU for gaming, then faster RAM is warranted.

http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3

I have a dedicated graphics card.

Yeah, I do want to ensure the life span of my PC. I did went through the BIOS the other day, setting it auto automatically sets the RAM to run at 1333 MHz at 1.5 volts.

I had to use XMP in order to get 1600 MHz.

 

[TheAvenger7]

Forgive the bump.

Reset the BIOS, RAM now runs at 1.5 v @ 1333 MHz. Should I leave it at that? I'm not noticing a dip in performance.

 

[gpse]

I would leave it, 1333mhz vs 1600mhz wont be noticed in real work, only in synthetic benchmarks.
Not to mention 1333mhz probably runs tighter timing than at 1600mhz, so the difference is really small performance wise.

 

[blastingcap]

Presumably timings would be the same if he simply downclocked without fiddling with timings afterwards. But as you can see in the link I linked to above, and again here: http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3/6

...it probably won't affect games. And if you are playing a movie or something it won't affect that either. It may affect certain programs that aren't that widely used (see rest of the review I linked to).

 

[Dave3000]

I have 16GB (4x4GB sticks) installed in my i7-3820 system. The stock voltage for them is 1.65v and I used to run them at the XMP profile stock settings with is 1600MHz at 1.65v. I've could run memtest 86+ for almost 8 hours without problems and it passed the Microsoft memory test. However I've been having problems with messages saying that Windows explorer has stopped responding in Control Panel and after clicking on view amount of RAM and processor speed, in the Control Panel. Also I got kicked out of Sleeping Dogs a few times. A few days ago I decided to set my memory to Auto settings which is 1333MHz at 1.5V in my motherboard's BIOS. It's stable so far but it was appearing stable at 1600MHz at 1.65v as well despite those issues I was mentioning, so I'm not sure if the 1.65V was causing stability issues since the i7-3820 does not support over 1.5v RAM. I think I might leave it at auto 1333 at 1.5v. I do get slightly slower performance in Cinebench 11.5's CPU test at 1333 at 9-9-9-24 than 1600 at 9-9-9-27, but only around 15 points lower. I also read posts saying that memory running in quad channel does nothing for gaming, so I presume that going down to 1333 9-9-9-24 from 1600 9-9-9-27 won't hurt gaming performance, especially since I'm running in quad channel mode?

 

[blastingcap]

I have 16GB (4x4GB sticks) installed in my i7-3820 system. The stock voltage for them is 1.65v and I used to run them at the XMP profile stock settings with is 1600MHz at 1.65v. I've could run memtest 86+ for almost 8 hours without problems and it passed the Microsoft memory test. However I've been having problems with messages saying that Windows explorer has stopped responding in Control Panel and after clicking on view amount of RAM and processor speed, in the Control Panel. Also I got kicked out of Sleeping Dogs a few times. A few days ago I decided to set my memory to Auto settings which is 1333MHz at 1.5V in my motherboard's BIOS. It's stable so far but it was appearing stable at 1600MHz at 1.65v as well despite those issues I was mentioning, so I'm not sure if the 1.65V was causing stability issues since the i7-3820 does not support over 1.5v RAM. I think I might leave it at auto 1333 at 1.5v. I do get slightly slower performance in Cinebench 11.5's CPU test at 1333 at 9-9-9-24 than 1600 at 9-9-9-27, but only around 15 points lower. I also read posts saying that memory running in quad channel does nothing for gaming, so I presume that going down to 1333 9-9-9-24 from 1600 9-9-9-27 won't hurt gaming performance, especially since I'm running in quad channel mode?

http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3/6

 

[Dave3000]

That system tested in that article was a system with dual channel memory. Maybe the difference would be even smaller on a system with quad channel memory since quad channel memory does not do much for games over dual channel memory?

 

[bononos]

I have two Kingston HyperX 4GB sticks running in dual channel at 8GB and at 1.65 volts in order to attain 1600 MHz.

However, I read that running RAM at that voltage with an Ivy Bridge CPU as its memory controller can officially support 5% higher or lower than 1.5 volts and it may be detrimental in the long run.
.......

5% over 1.5v is still lower than 1.65. Sandy's and Ivy's don't support 1.65v (at least not officially) memory and running it that high could cause the cpu to kaput.