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Overclocked Memory Breaks Core i7 CPUs
arcticstoat writes "Overclockers looking to bolster their new Nehalem CPUs with overclocked memory may be disappointed. Intel is telling motherboard manufacturers not to encourage people to push the voltage of their DIMMs beyond 1.65V, as anything higher could damage the CPU. This will come as a blow to owners of enthusiast memory, such as Corsair's 2.133MHz DDR3 Dominator RAM, which needs 2V to run at its full speed with 9-9-9-24 timings."
I understand the mindset, obligatory car analogy here, but it is not something I've ever done. Shopping for hardware has become a bit of a mine field lately, as most of the top tier motherboard and RAM manufacturers offer a *ton* of options for boosting the juice to various things all over the motherboard. They advertise this as a feature. I'm glad for those folks who like to go faster. It does make things a bit tricky having to check the RAM voltage, against what the motherboard can handle, and the processor will take, and hoping it all works. I'd like it if Asus and Gigabyte could maybe come up with a 'Get off my lawn!' series for us folks who like stock voltages, and wear onions on our belts.
Have you ever tried booting some of this memory with the default timings on a motherboard to find it will not boot with overvolting? I bought 8gb of OCZ memory this summer and could not get my system to boot till I took out some other memory from a Dell my company gave me and overvolted that memory in BIOS to 1.7 and than swapped in the 8gb OCZ. I should not have to do that, doesn't the memory specify what voltage it needs to run at; and if not, why not?
An Education is the Font of All Liberty
Well the downsizing of the cpu transistors make them "faster" but also more fragile.
To be more specific overvolting is not a problem for the transistor itself but it is a problem for the interconnections due to the effect of Electromigration http://en.wikipedia.org/wiki/Electromigration.
The interconnections of latest CPUS are so thin that +0.15 could mean a lifespan cut of 50% or more. While higher values could mean a lifespan of months instead of years!
Its true that overclocking was always said to be a dangerous practice while actually till 1-2 years ago wasn't (with a proper cooling), but now we are using something that can be less and a hundred atoms wide!
Actually intel is frightened that a too common "high" overvolting pratices could make their CPU seem less reliable (well they are but is a intrisic problem not an intel fault)
Unluckily Murphy was right.
Buy DIMMs that work at lower voltages because they use smaller processes or buy motherboards that separate the refresh power circuits from the data circuits on your RAM. It's doubtful that the data lines need 1.8 or 2.1 volts or whatever.
I think you overclocked your cognitive processor!
Armed with the knowledge that the PN junction voltage drop of a Diode is 0.7v, and either no forethought, or no knowledge beyond that at all in the hardware domain, you have managed to make a very absurd statement (no offense.)
I'm not going to get into the myriad ways that this is absurd and impossible, but lets start (and end) with the fact that you can't just start soldering things on a board when things are clocked in the Gigahertz range from a theoretical standpoint even if you could violate the laws of Physics and hand solder a diode between the IC Pin and the motherboard.
Cheers!
Guns don't kill people; Physics kills people! - John Lithgow as Dick Solomon on Third Rock From The Sun
I've never noticed it in gaming, but matching the latency to the CPU timing can noticeably affect video encoding. Changing my ram from stock 3-3-3-5 to it's full supported 2-2-2-3 decreased encoding time significantly with no other changes to the machine.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
No, they're lower binned parts that couldn't make "enthusiast" OR normal speeds at 1.5 volts.
They crank up the voltage and re-rate them at a higher speed, and slap on ridiculous cooling (heat spreaders, heat pipes, built in fans).
They KNOW these pieces will fail at high rates, so they jack up the price and call it gamer/enthusiast RAM. When the return rates start to drop off, they start issuing rebates to move remaining stock.
1. The N-wells are typically connected to one of the power supplies.
Which one is dependent on the design and what supplies are being used in
that circuit. If the well bias gets more than a diode drop below the
voltage that the Pfet is connected to, current will flow raising
disipation, and potentially causing latchup.
when multiple voltage come into play and start to
leak, you can expect side effects like latch up or a higher voltage going to
a low-voltage region of the chip and frying your transistors which have only
a few atoms of isolation (typically, the IO is made with thicker oxide FETs
to run higher voltages than your core in order to pump the nescessary energy
fast enough to the peripheral chips).
2. If you have too much current flowing from one part of the chip to
another. Even if it comes from the same supply, the current drawn would be
too much to handle (imagine powering you CPU with 1 pair of pins instead of
the 100s they use). In this case, your electrical connection melts away like
a fuse.
3. Some high voltage outputs may use multiple supplies and depend on
values of each to avoid overstressing...
4. Some level shift circuits might depend on power supply being in
tolerance..
Actually if you apply too much voltage to the gate of CMOS transistor you can exceed the breakdown voltage of the gate oxide which, as I recall, scales with oxide thickness which itself scale inversely with process node. So actually "overvolting" can be a problem for the transistors, although I admit I don't know if electromigration or oxide breakdown dominates as a failure mechanism given the minor voltage changes we are talking about here.
I've seen this too. The problem is that the RAM companies have marketed this overclocker RAM as "better", even though it won't run in DDR2 spec.