On Tue, Sep 16, 2008 at 11:24:40PM -0400, Andrew Miklas wrote: > Hi, > > On 16-Sep-08, at 7:44 PM, Arno Wagner wrote: > > >hat do you want multicore support for ayways? Do you have an > >application that can actually saturate even one core? Multicore > >sounds like basicelly costing a lot of effort and postential > >problems for nothing in return. > > I have an application where I definitely need multicore support. But it is just you, i.e. < 1% of the users and likely 0% of the developers. > I've > got a server running a I/O bound application over a RAID array capable > of 150+ MB/s. All the data stored on disk needs to be encrypted. > Unfortunately, my I/O throughput caps out at around 80-90 MB/s, even > though there is plenty of spare CPU power (it is a quad-core system). You might actually have a rare case for crypto acceleration hardware. Maybe you should look into that. Typically it is used when really high performance is needed. The Linux kernel supports some. You may also want to leave PC hardware behind. The IBM z10, for example, has hardware AES. If it is possible to distribute the data on several disks, that may also help. My guess is thet it is not the crypto, that is single CPU, but the actual disk I/O for one disk. Doing locking and synchronizarion here could actually hurt performance and would be very difficult in any case. You can also try to go back to a high-performance dual core CPU, there are some around where the individual cores are notably faster than in the quad-cores oyt there. If you need the CPU power for the application, try going dual-dual core. Example: For AMD, the X4 9950 Black Edition seem the fastest quad-core out there, that you can actually buy. The CPUs run at 2.6 GHz. But you can also get a X2 6400+, with 3.2 GHz cores, i.e. 23% faster. Come to think of it, the Via C7 is slow, but its hardware AES can do a maximum of 2.5GB/s for AES encryption. Use that in a fileserver and then transfer over with 10 Gb Ethernet? > I admit that needing full-disk encryption on a server is probably a > bit of a rarity, but there are a few of us out here that actually need > to do that. :) And hence you get either bad support or it gets very expensive. Though, but unavoidable. My guess is that your best bet is not to look for a software solution, but to get faster hardware, whether PC or not. Arno > > -- Andrew > > --------------------------------------------------------------------- > dm-crypt mailing list - http://www.saout.de/misc/dm-crypt/ > To unsubscribe, e-mail: dm-crypt-unsubscribe@xxxxxxxx > For additional commands, e-mail: dm-crypt-help@xxxxxxxx > -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@xxxxxxxxxxx GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier --------------------------------------------------------------------- dm-crypt mailing list - http://www.saout.de/misc/dm-crypt/ To unsubscribe, e-mail: dm-crypt-unsubscribe@xxxxxxxx For additional commands, e-mail: dm-crypt-help@xxxxxxxx
