Memory voltage questions

[redwudz]

One question I haven't resolved with memory concerns the 2.1V memory I have running in a 1.8V motherboard with no memory voltage adjustments available. It seems to run perfectly well, but I haven't been able to find if this will be a problem.

I have the same memory in a MB that I was able to adjust the voltage to 2.1V and it seems to run just the same. I suspect running at a lower voltage than it's rated for may mess up the timings, especially for overclocking. I understand running at a higher voltage than the memory is rated for is likely to overheat and damage the memory.

So I guess my question is, outside of overclocking, is using a lower voltage going to cause problems?

I've looked on several forums, including Corsair's memory forum and didn't find much information there either.

The memory I'm using is CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)

[videobread]

I have had similar questions. My HP Workstations call for and came with 2.5 volt RAM. Crucial.com shows 2.6 volt RAM. I use it and it works fine. I think if the RAM voltage is a little higher then it's OK. If the RAM voltage is lower then you might have problems.

[trhouse]

Corsair is not a manufacturer of dram. They buy product to integrate. To find the actual specification for the part requires identification of the chip maker.

Most dram have a voltage tolerance of at least +0.1 to -0.1 volt as shown on this Micron datasheet. Some Hynix parts are more generous at +0.2 to -0.2 volts as shown on their sheet. Within these parameters, the parts are guaranteed to meet all specifications.

http://download.micron.com/pdf/datasheets/dram/ddr/512MBDDRx4x8x16.pdf

http://www.hynix.com/datasheet/eng/consumer/details/consumer_02_HY5DU12822CFP.jsp?menu...u2=02&menu3=02

[redwudz]

From what I can find, running at a slightly lower voltage should be OK most times. But the timings may not be up to specification for the speed you are running for the memory. With the PC that I was able to adjust the voltage to the proper 2.1V, I can change the timings to 4-4-4 when overclocking the FSB to 230Mhz.

The other PC without voltage adjustments, and set at 1.8V, runs at 5-5-5 when similarly overclocked. But it doesn't have timing adjustments either, so it's hard to compare. So it seems this is generally not a problem unless you are overclocking and want to use tighter timings. Both PC RAM modules run at 4-4-4 at 200Mhz FSB frequencies. But if I raise the FSB up to 230Mhz, the lower voltage module can't be adjusted to 4-4-4 while the module set to the proper 2.1V allows this.

Just checking RAM temps, the ones running at 2.1V run a bit warmer, but only a few degrees C and well within tolerance. As the voltage increases, so does the temperature. If it were raised to 2.5V for a 1.8V RAM module, that would probably cause it to overheat and may damage the module.

As trhouse, mentions, you would have to read the RAM chip's name and model off the chip itself and download the actual chip manufacturers data sheet to find out the true specifications for that RAM chip.

[Krispy Kritter]

Generally speaking, when OC'ing memory, you increase the voltage to get higher speeds and tighter timings. Lack of adjustments for voltages, timings, etc. is a BIOS limitation and shouldn't be affected by the type of memory used in the MB. Meaning if the BIOS allows changes to the voltage (for example), it should allow changes to the voltage for all memory.

You would likely get a much better explanation over at a site such as the forums here: http://hardocp.com/

[RabidDog]

My memory allows running at a std 1.8v but is also certified to run at 2.2v . Generally for overclocking you need more power, but this causes components to heat up, but apparently this is not a massive problem for good quality memory.