NAS Charts

[gportellihale]

Hi

While I was checking the performance of the new NASs that were currently released I came across the following note on the NAS charts web pages:

NOTE: The maximum raw data rate for 100Mbps Ethernet is 12.5 MBytes/sec and 125 MBytes/sec for gigabit Ethernet. Throughput above these values is due to memory caching effects in the client OS and NAS under test.

I cannot understand how you can obtain a higher throughput than Ethernet's RAW data rate which can be attributed to cache on the NAS. That you can obtain higher throughput because of cache on the client side I can understand, but on the NAS side, I simply am at a loss as how the cache on the NAS can boost the data rate to a value higher than the RAW data rate.

Can someone please explain?

Thanks

George

 

[thiggins]

It can't.

How about:
"Throughput above these values is due to memory caching effects in the client OS and /or NAS under test."

 

[gportellihale]

How about this than:

"Read throughput above these values is due to memory caching effects in the client OS."

From what I understand throughput higher than the RAW data transfer are only possible if the file you wrote to the NAS is being now read and it fitted in the client OS's cache, therefore instead of the OS reading from the NAS it reads from it's own cached copy.

Is the above right?

 

[thiggins]

Yes. That's correct. But I prefer the more general, shorter note.

 

[gportellihale]

Thanks for the clarification. I wanted to know if I was missing something.

Regards