IDE RAID vs. 100Mb Ethernet...

[Quaggoth]

My Boss seems to think that our "bottleneck" is in the fact that we are using an IDE RAID setup for our image server and NOT the fact that the data is being transported via 100Mb ethernet. What is the best way to explaine to him that IDE RAID is VERY MUCH not the bottleneck? I am trying to make the case for Gigabit ethernet.

 

[SpeedFreak03]

Well use numbers! Im not sure what the maximum rate for IDE RAID is, but lets say its 133MB/s. Since 133 > 100, the 100 is the bottleneck! I know that regular IDE drives cant saturate a ATA66 bus though. Either way good luck!

-Josh

 

[Ionizer86]

Let's do it this way. Modern hard drives can sustain about 60MB data transfer. If you RAID 0 them, the max is 120MB/s.

100Mb/s ethernet is 12.5MB/s (8 bits is a byte). So 100 megabits is only 12.5 megabytes. So now, it's very obvious that the 100 megabit is the bottleneck, not to mention that 12.5 is the theoretical performance. (Actual performance is more like 7MB/s on my network).

Upgrading to 1000MB/s ethernet will yield a theoretical bandwidth of 125MB/s. The actual performance will be much lower (maybe 60 to 70MB/s) but it will be sufficient to not bottleneck too badly.

 

[WobbleWobble]

Originally posted by: SpeedFreak03
Well use numbers! Im not sure what the maximum rate for IDE RAID is, but lets say its 133MB/s. Since 133 > 100, the 100 is the bottleneck! I know that regular IDE drives cant saturate a ATA66 bus though. Either way good luck!

-Josh

Actually, you're kind of wrong here. Yes, the 100Mbit LAN is the bottleneck, but you're comparing bits to bytes. It's 133MBytes/s for ATA133 and 100Mbits for the ethernet connection.

 

[yhelothar]

My IDE raid sustains about 86MB/s, which consists of two Maxtor 160GB 8MB cache drives
doesn't sound like 12.5MB comes close

 

[Blain]

Time to play into his fears and go to a Rocket Drive!

 

[zephyrprime]

Switch to no raid at all and show him the same performance.

 

[EeyoreX]

Let's do it this way. Modern hard drives can sustain about 60MB data transfer. If you RAID 0 them, the max is 120MB/s.

I hope that this 120MB/s is theoretical... One person mentioned 86MB/s with his RAID configuration. That's a pretty good speed. Well above average for most typical RAID0 configurations. Regardless, the network is your bottle neck either way.

\Dan

 

[Ionizer86]

The 120MB/s isn't theoretical, but it's assuming the best conditions where you double the actual max performance of modern drives. I doubt that RAID 0 will actually double drive performance from 60MB/s to 120MB/s except under rare cases. In any case, it's obvious that the 12.5MB/s theoretical on 10/100 is the bottleneck.