-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 1/28/2014 2:46 AM, Stan Hoeppner wrote: > You usually must submit asynchronously or in parallel to reach > maximum throughput. Being limited by a PMP it may not matter. But > with your direct connected drives of your production array you > should see a substantial increase in throughput with parallel > submission. Not for streaming IO; you just need to make sure your cache is big enough so the drive is never waiting for the app. > To significantly increase single streaming throughput you need AIO. > A faster CPU won't make any difference. Neither will a better SATA > card, unless your current one is defective, or limits port > throughput will more than one port active--I've heard of couple > that do so. What AIO gets you is the ability to use O_DIRECT to avoid a memory copy to/from the kernel page cache. That saves you some cpu time, but doesn't make *that* much difference unless you have a crazy fast storage array, or crazy slow ram. And since almost nobody uses it, it's a bit of an unrealistic benchmark. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (MingW32) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJS6rpiAAoJEI5FoCIzSKrw6oMH/jDcFOs8Gu2wjbbuE1eoGtG7 aHeUvF6klWWV5VWCVBd4tHieVkj1zyg3nQa3DGaOvqBnz6mtIQUx6Pg5MgYkJAhD EY1f3zVH+hxBEyJwwmMIDIyVsDCbdsryKndfPuYolaqNSgXLyWpAcL6g/SM9vjoG nH29w1GC3TJP5Py1DNP4P04Q+kJMTYnY/4AFJOtsMRK5XRpno784YZauS/basEH3 rpSf/JvhcZMbk6nE8jkqIYnMbA35E8f+GfSa60epqDSSM3hU5U1xYnh6vCZSSndK pMCFv26O9AVoFdyPZTJwM32gqGXdsGkDanK2+0y/j2im5IT0PxKCWO+uCLO/1mQ= =9NYg -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
