ashford posted on Sun, 20 Jul 2014 12:59:21 -0700 as excerpted: > If you assume a 12ms average seek time (normal for 7200RPM SATA drives), > an 8.3ms rotational latency (half a rotation), an average 64kb write and > a 100MB/S streaming write speed, each write comes in at ~21ms, which > gives us ~47 IOPS. With the 64KB write size, this comes out to ~3MB/S, > DISK LIMITED. > The 5MB/S that TM is seeing is fine, considering the small files he says > he has. Thanks for the additional numbers supporting my point. =:^) I had run some of the numbers but not to the extent you just did, so I didn't know where 5 MiB/s fit in, only that it wasn't entirely out of the range of expectation for spinning rust, given the current state of optimization... or more accurately the lack thereof, due to the focus still being on features. -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
