DDR667 @ DDR800 Voltage increases

nlel1975 · 27 May 2007 at 14:09

Is it just a case of upping the voltage from 1.8v to 2.1v in most cases. I`m getting Crucial (Micron) PC5300 and although my max overclock will probably be on the 333fsb I`d like to try 375fsb with PC5300 RAM. I`ve done a bit of reading and it seems you just have to increase the voltages to 2.1v.

Anyone doing this and has anyone ever killed a stick of RAM by doing this.

WJA96 · 27 May 2007 at 15:36

What Crucial RAM are you using? The vanilla stuff or the Ballistix with the Yellow heatspreaders?

If it's the vanilla stuff, then they usually do PC6400/800MHz at 5-5-5-20 without a voltage hike, but the Ballistix stuff runs much tighter timings, even at PC5300/667MHz and it's rated at 2.2V. Aim for PC6400/800MHz 4-4-4-12 if it's Ballistix.

Depending on where the RAM builder bought their PCBs from (I kid you not) some of them will have voltage regulators built-in (I think all newish Corsair does, but don't hold me to that) so you could feed 3V through them and the RAM either just shuts down or disappates the extra voltage as heat - the RAM chips only see what the voltage regulator allows through - usually about 10% over the memory's rated maximum.

2.5V is known to be damaging to Crucial/Micron RAM chips because of a phenomenon called Electron Migration, so you shouldn't ever run Micron RAM over 2.4V if you're smart.

2.2-2.3V is fine though and don't forget Crucial have a very fast lifetime RMA service if they should go wrong.

nlel1975 · 27 May 2007 at 16:08

Its the "Vanilla" stuff CT2KIT12864AA667 so you reckon I`ll be able to run it at up to DDR800 speeds with only 1.8v but shouldn't worry about giving it 2.1v if I need too. Right thats sorted then.

WJA96 · 27 May 2007 at 16:48

Ignore that - yes, you should be able to get PC6400 on that without a voltage bump.

And you may want to remove the competitor link

nlel1975 · 27 May 2007 at 19:20

I looked on the Crucial website and it doesn't give the timings only CAS5. Is 5-5-5-20 the exact timings or is it the slowest you can set which you would do if running at up to 800mhz seeing as its rated 667mhz @ CAS5.

WJA96 · 27 May 2007 at 19:35

Leave the timings on AUTO and turn up the FSB. It'll give you something close to 5-5-5-30, and you should be able to tighten it up to 5-5-5-20, but as you're overclocking, nothing is guaranteed.