On 3 Sep 2013, at 12:57, lot...@denx.de wrote: > Am 2013-09-03 00:16, schrieb Chris Tapp: >> On 2 Sep 2013, at 22:45, Christian Gagneraud wrote: >>> On 03/09/13 00:35, Burton, Ross wrote: >>> Hi Ross, >>>> On 2 September 2013 06:05, Christian Gagneraud <chg...@gna.org> wrote: >>>>> So right now, I'm thinking about: >>>>> - CPU: Xeon E5, maybe 2 x E5-2670/90, for a total of 16 cores (32 threads) >>>>> - Hard drives: 500GB, 1 TB or 2 TB (ideally with RAID if it can speed up >>>>> the >>>>> builds) >>> RAID-5 seems to be what i am after. >> Isn't RAID-5 going to be slower, especially if it's software? RAID 1 >> is probably better as you'll potentially double the write speed to >> disk. I use a couple of Vertex SSDs in RAID 1 giving a theoretical >> write speed near to 1GBs. Write endurance is possibly a concern, but >> I've not had any issues using them on a local build machine. I would >> probably look at some higher end models if I was going to run a lot of >> builds. A lot less noise than hard drives ;-) > > Hi, this sounds interesting to me. > > Having a brief look into wikipedia ( http://en.wikipedia.org/wiki/RAID ) > tells me that RAID-1 gives no increase in write speed at all (for sequentioal > operations), by theory: 1x ...while a RAID-5 at least in theory, should > give you: (n-1)x, assumed the hardware is fast enough to support it (RAID > controller!).
Quite right. That'll teach me to hack out an e-mail late at night whilst packing for a road-trip :-( I meant to say RAID 0. > > Having had a small conversation here, I was told we even made experiences on > having HW RAID being slowed down by the RAID controller, and its limitation > of I/O-operations, that still could be handled. So, it seems to me one > motivation why using SW RAID instead of HW RAID is exactly to overcome this > limitations of having the bottleneck of a RAID controllers. > > Question, running RAID-5, have you tried to adjust the chunck size? In our > case most I/O operations are on relatively small text files and may require > some adjustment to the RAID chunck size value in respect to that fact. No, mainly because two SSDs for RAID 0 was enough cash to spend ;-) > > BR, > Lothar Rubusch > _______________________________________________ > yocto mailing list > yocto@yoctoproject.org > https://lists.yoctoproject.org/listinfo/yocto Chris Tapp opensou...@keylevel.com www.keylevel.com _______________________________________________ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
