Overclocking / Modding → Memory overclocking guidance

I have some CORSAIR Vengeance 8GB (2 x 4GB) DDR3 SDRAM DDR3 1600 (PC3 12800) memory in my PC at the moment w/a Asus P8Z68-V mobo.

I've successfully overclocked my CPU (Core i5 2500K) @ 4.7Ghz. And perhaps most important, it's stable. But I haven't been able to successfully overclock my memory passed 1600Mhz. I've gotten it to 1866Mhz using 1.6v, but it eventually craps out. I'm just not sure how much voltage is too much for desktop memory, so I don't want to mess with the voltage too much and risk frying something.

What is the safe amount of voltage when it comes to memory? Like I said, 1866Mhz @ 1.6v the memory/system allowed me to run the Intel Burn Test v2 with "Very High" settings. Although the test came back stable, it wasn't until I started gaming that the system locked up (which I think was due to the memory).

The current (1600Mhz, not overclocked) timings are set at 8,8,8,24, 2T.

You pretty much no longer OC the memory, asking for 1800 out of 1600 ram is alot... and no one can really say what the stuff will take... (as with any overclocking) you really see no benefit from getting more "speed" you will likely need to loosen the timings... (so now you access slower)

IMHO I'd leave it... if anything work on making the timings tighter... but the performance gain is like nothing either way.

Now, when you say tighten the timings you mean lowering their values, correct? ie 8-8-8-24 to 7-7-7-20

Btw attached pic shows the current timing set for my memory.

Yes, however you can get like 7-8-7-20 (saying it does not need to be the same 777 666 888 etc) that will allow you computer to access the info faster (however no bandwidth gain as you would get with clock speed) Without knowing your uses... who can say if you are bandwidth limited or if access time would boost you a little.

IMHO... the gains aint worth the work... ram used to matter alot more when you could not OC by the multi and you had to up the FSB thus overclocking the ram as well...

If you really want to get more out of it... I would say if the info here is not enough (I myself aint being very helpful lol) these guys should should know if it possible and how to do it »www.overclock.net/

"What is the safe amount of voltage when it comes to memory? Like I said, 1866Mhz @ 1.6v"

I wouldn't go above 1.6. Intel recommends against anything beyond 1.6-1.65. You can damage the cpu.

1.65v is DDR3 stock voltage, 1.6v would be undervolting it unless you're using low power ram which is kinda pointless in a desktop machine.

Intel SB CPU recommends 1.5 volts with +/-5% so 1.58 volts max, it has been "tested" to 1.65 and okay but the intel spec is 1.5volts.

Intel whatever before SB was 1.65 per intel specs for the CPUs memory.

1.5 volts is not undervolted persay as much as it is spec for SB cpu's.

That's Intel's problem. Since the vast majority of DDR3 is 1.6-1.65v as it's been since the days where the only thing using DDR3 was the high end Core2 series mobos.

Just set it to the XMP profile and forget about it. There's not much performance to be gained OCing RAM, especially above 1600, anyways (unless you have integrated graphics).

»www.newegg.com/Product/P ··· hInDesc=

~250 sets of ddr3 at 1.5 volts... hardly a problem...

So no the vast majority is not... actually on newegg the vast majority is 1.5 volt not 1.6-1.65.

Most DDR3 1600 ram these days is 1.5v or less. Why you would say that is kinda pointless on a desktop is beyond me.
If you're willing to loosen the timings SB boards can OC the ram very well. 1333 MHz ram running @ 1923Mhz @ 9-9-9-24

First off the board never does overclocking... the northbridge did (okay I guess you "could" call that the board) but it was not limited to the chipset, it was limited to what the ram could do (till you went outside what it would support or issue with upping the FSB too much)

Next SB the boards do nothing for the ram, it is alllllll on the CPU... so if anything it would be SB CPU's oc ram well... but again... unless you try to go over the SB memory controller supported speeds... it aint the CPU but all what the ram can do...

So bottom line... to get anything under what, 2000 on SB at least (forget what SB supports 2300 or something), is all ram, not "board" or cpu.

That being said, that sort of OC is alot... however you are trading access time for bandwidth... but ah... I hate ram so... does clock speed negate the access time lose... blah who knows... F ram lol.

But ya most ram is not gona get that kinda OC, it aint that good.

My point was that the OP could probably get get more ram speed with looser timings. Whether there is any benefit to that is debatable.

No.. it's the user's (and OPs) problem. He asked how far is was safe to push it, the answer is up to 1.58v on SB because the memory controller located on the CPU itself cant take it (not that the physical RAM cant take it).

I just picked up an Kingston 1GB dual channel kit of DDR2 800 but my Pentium 4 motherboard will only run it at 667. Is there any thing I can do to increase the speed? It is an VIA PT880 Pro and 8237/R chipset. The BIOS will let me change the CPU host speed to increase the FSB and CPU speed but I think it can also change the RAM clock.
Default is: CPU Host speed (200Mhz),
Multiplier x16 Locked
FSB: 800Mhz
There are a few other settings that my BIOS has for the RAM.
DRAM Command Rate 1t or 2t. Is 1t better?
DRAM Voltage
DRAM CAS Latency
My motherboard: »www.asrock.com/mb/overvi ··· l-880Pro
CPU: Intel Pentium 4 540J
RAM: 1GB DDR2 800 (running at 667)

Looks like the chipset only supports 667. Have to overclock CPU to go higher.

lol overclocking memory on that thing is like putting more horse power into a lawnmower... gona cut the grass at the same speed.

these are what I have found:

Intel Cpu's prefer higher clocked memory with looser timings.

amd cpu's though prefer lower speed memory with tight timings.

both AMD and Intel specify no more than 1.65V Vdimm on DDR3 as any higher can damage the memory controller in the cpu.

DDR3 can handle higher voltages though without damage. but the memory controller is the limiting factor.