On Fri, Aug 19, 2011 at 09:41:50PM +0100, David Given wrote: > On 19/08/11 21:13, Lennart Sorensen wrote: > [...] > > /dev/sda: > > Timing cached reads: 512 MB in 2.00 seconds = 255.59 MB/sec > > Timing buffered disk reads: 134 MB in 3.01 seconds = 44.49 MB/sec > > > > /dev/mmcblk0: > > Timing cached reads: 490 MB in 2.00 seconds = 244.49 MB/sec > > Timing buffered disk reads: 36 MB in 3.09 seconds = 11.63 MB/sec > > 44 MB/s is surprisingly slow for SATA; that's (anecdotally) about what > the TrimSlice gets through its emasculated SATA-via-USB interface.
It's a 5400rpm laptop drive. Perfectly normal. It happened to be lying around unused. I didn't expect it to be any faster. The fact it doesn't use a ton of CPU cycles to do 44MB/s unlike the microSD makes a much bigger difference. I will probably try with a real full size SATA drive later. > For comparison, my SheevaPlug gets: > > /dev/sda: > Timing cached reads: 568 MB in 2.00 seconds = 283.81 MB/sec > Timing buffered disk reads: 78 MB in 3.06 seconds = 25.50 MB/sec > > /dev/mmcblk0: > Timing cached reads: 564 MB in 2.00 seconds = 281.88 MB/sec > Timing buffered disk reads: 56 MB in 3.02 seconds = 18.57 MB/sec > > /dev/sda is a 64MB Kingston SSD (feeling, I expect, extremely frustrated > at being hooked up via USB). Interesting that the cache read figure is > faster on the SheevaPlug, isn't it? Yeah USB hurts. Wastes tons of CPU cycles. I am not sure what the ram specs are on the sheeva versus the imx53. > [...] > > MEMORY INDEX : 5.943 > > INTEGER INDEX : 5.664 > > FLOATING-POINT INDEX: 1.669 > [...] > > I guess that's quite a bit faster than your sheevaplug then. Especially > > on floating point. No idea if the default gcc settings the makefile > > used are even ideal. > > Memory's about twice as fast, integer about 20%. Not as much difference > as I would have thought... I compiled mine with -O3. They are both single core and about the same clock speed as far as I recall. > Anyway, thanks very much --- interesting to see the figures. -- Len Sorensen -- To UNSUBSCRIBE, email to debian-arm-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20110819204530.gr15...@caffeine.csclub.uwaterloo.ca
