Dear Richard, Matt, fsbuild,

First of all I would like to thank you all for your quite informative answers. I am aware of the way ECC memory works, but your answers provided new and interesting information.

However, my question is about the criticality of ECC memory specifically for Freesurfer. I know for example that for financial computations where high precision is required one should use ECC memory while for video encoding tasks non-ECC is the memory of choice since the lack of computational accuracy coming from non-ECC memory has a minimal (if at all) effect on the end result.

Given that Freesurfer is used for medical-oriented research, is ECC memory something that should be required of a system running Freesurfer or its effects are not significant according to the experts of the field and your experience?

Regards,

Sotiris Michos

On Tue, 8 Oct 2019 at 02:19, R Edgar <freesurfer.rge@gmail.com> wrote:

On Mon, 7 Oct 2019 at 02:41, fsbuild <fsbuild@contbay.com> wrote:

> For this to work, I think the (hardware) memory controller and the CPU need to support ECC as well. So if the motherboard you are spec'ing out does not explicitly say it supports ECC, then I would assume it does not. ECC memory is 2X to 3X more expensive than non-ECC memory. I don't know how motherboard prices compare that do/do not support ECC. Users who are building machines for supper fast gaming, or audio/video production and streaming typically won't spend extra money on ECC as they want to max out on the CPU, memory, and buss/bandwidth.

I'm not sure about the AMD side, but for Intel you generally have to
go to Xeon chips and motherboards to get ECC support. See the "memory"
section under:
https://www.intel.com/content/www/us/en/support/articles/000006778/processors.html
ECC will in general be (slightly) slower than 'regular' RAM due to the
extra parity bits.

HTH,

Richard