Given that I'm sending this from a works email I really hadn't better comment about corporate SAN performance, apart from saying that what I like to do on my servers is to run fast file systems on local SSD which are then mirrored using MDADM to a SAN in write-mostly mode. This way all the reads just come off SSD putting no i/o load on our SAN which only has to handle write i/o, something it does pretty quickly.
But leaving work behind an back to a better reality, disks may be cheap now but enclosures to hold the minimum 4+ disks required for a raid10 array aren't, certainly not within my home budget anyway. For me it's a simple mirrored pair in a home SAN for bulk storage and simple SSD for speed. If I needed those big disks to be faster I think I'd try bcache rather than raid10. Rob. -----Original Message----- From: Nick Payne [mailto:[email protected]] Sent: 23 March 2013 01:24 To: [email protected] Subject: Re: [Darktable-users] Difference between i7 processors for Darktable On 22/03/13 22:47, Patrick Shanahan wrote: > * Michael Schuster <[email protected]> [03-22-13 02:10]: > [...] >> "export" sounds like I/O, so if that's your perceived bottleneck, >> perhaps you should measure first whether that's really the case -- if >> this were Solaris, I'd say "use iostat, then DTrace", I don't know >> what Linux offers here; the one I use at work seems to know iostat at least. >> >> If the suspicion about I/O is indeed correct, fiddling with the CPU >> specs won't gain you much, I'd then much rather invest in a >> (bigger/nother) SSD and/or more RAM. > Yes, in modern boxes i/o is the bottleneck not cpu. Investing in an > ssd drive at least for operating system and sata-3 raid-5 fast hard > drives will help tremendously. If you're going to go beyond using single disks, then given how cheap disk is these days, RAID-10 makes more sense than RAID-5 if performance is what you want. The performance is better (no parity to write), redundancy is better (even two failed disks won't take you out unless they happen to be a mirror pair), and in the event of drive failure and replacement, array performance while the rebuild is taking place is markedly better. In the 25 or so years I've been supporting RAID arrays on LANs (and more recently SANs), it's gone from being RAID-5 if you wanted redundancy to hardly ever seeing a RAID-5 array any more. Nick ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_mar _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users The content of this email is private and confidential, and unless otherwise stated only the intended recipient may use the content of this email for its intended purpose. If you are not the intended recipient, you may not retain, copy, forward or disclose the information herein, and we ask you to notify the sender or contact our Customer Services department on 0844 633 1000 or at [email protected] The copyright and all other intellectual property rights subsisting in or to the contents of this email belong to NHBC or are used with the permission of the owner and all such rights are reserved. Recipients are asked to note that opinions, conclusions and other information in the contents of this email that do not relate to the official business of NHBC are neither given nor endorsed by NHBC. This email has been scanned for viruses, but NHBC does not accept any liability in respect of loss or damage caused by any virus which is not detected by its virus detection systems. Data Protection Act 1998. NHBC is the Data Controller for the purposes of the Act. Your personal details will be stored and processed in accordance with the Act for the purposes of dealing with your enquiry or claim and for research and statistical purposes. If you make a claim under a Buildmark policy you agree to your data being passed to others involved with your claim such as the original builder, or a consultant or remedial works contractor that we may employ in connection with your claim(s) and matter ancillary to your claim(s). Other than disclosure provided for in this statement, we will not pass any data about you to any other party without your permission unless we are required to do so by law. NHBC, the National House-Building Council, is a company registered by guarantee in England, registration number 320784, and it is authorised and regulated by the Financial Services Authority. ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_mar _______________________________________________ Darktable-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/darktable-users
