Bart Van Assche wrote: > On Jan 24, 2008 8:06 AM, Robin Humble <[EMAIL PROTECTED]> wrote: > >>On Tue, Jan 22, 2008 at 01:32:08PM +0100, Bart Van Assche wrote: >> >>>............................................................................................. >>>. . STGT read SCST read . STGT read >>> SCST read . >>>. . performance performance . performance >>> performance . >>>. . (0.5K, MB/s) (0.5K, MB/s) . (1 MB >MB/s) >>> (1 MB, MB/s) . >>>............................................................................................. >>>. Ethernet (1 Gb/s network) . 77 78 . 77 >>> 89 . >>>. IPoIB (8 Gb/s network) . 163 185 . 201 >>> 239 . >>>. iSER (8 Gb/s network) . 250 N/A . 360 >>> N/A . >>>. SRP (8 Gb/s network) . N/A 421 . N/A >>> 683 . >>>............................................................................................ >> >>how are write speeds with SCST SRP? >>for some kernels and tests tgt writes at >2x the read speed.
Robin, There is a fundamental difference between regular dd-like reads and writes: reads are sync, i.e. latency sensitive, but writes are async, i.e. latency insensitive. You should use O_DIRECT dd writes for the fair comparison. Vlad _______________________________________________ Stgt-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/stgt-devel
