Re: [Freesurfer] ECC or non-ECC Memory?
External Email - Use Caution Dear all, This is just to close up this question. After some correspondence with the lab's members, I was informed that due to the imaging nature of the software ECC is not "needed" but advisable. The lab's computers are all equipped with ECC memory. However, a double run of an analysis is deemed adequate to over come the rare case of any such errors, even when non-ECC is used. I would like to thank everyone who contributed to this questions with their comments as well as the lab's members that assisted me with this issue. Best Regards, Sotiris Michos ___ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Re: [Freesurfer] ECC or non-ECC Memory?
External Email - Use Caution Dear Matt, Memtest 86+ and similar tools can test the DRAM module only for hard errors (hardware defects). Are you suggesting that the soft errors (the common spontaneous flipping of a bit state) that happen in all memories do not have a considerable effect in Freesurfer’s results? Best Regards, Sotiris ___ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Re: [Freesurfer] ECC or non-ECC Memory?
External Email - Use Caution 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 wrote: > On Mon, 7 Oct 2019 at 02:41, fsbuild 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/06778/processors.html > ECC will in general be (slightly) slower than 'regular' RAM due to the > extra parity bits. > > HTH, > > Richard > ___ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
[Freesurfer] ECC or non-ECC Memory?
External Email - Use Caution Dear Freesurfer community, I am interested in building a PC with the goal of running Freesurfer (about 2000-2500 Euros). I have carefully read this <https://surfer.nmr.mgh.harvard.edu/fswiki/SystemRequirements> very informative webpage. However, I still have some questions and I would be glad if some assistance could be provided. I suspect that a proper PC would be placed towards the workstation side of the spectrum, since from what I read in the above webpage, Freesurfer can utilize multiple cores and is quite demanding in RAM memory per instance. What I would like to ask is whether ECC Memory is critical for this application or if the corruption coming from a non-ECC module has any significant effect on the end result. Also, any advice or suggestions about the system's buildup would be more than welcome. Best Regards, Sotiris Michos ___ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
