Since I've seen a bunch of questions on various NAS forums on data transfer performance, here's a quick post on the performance I observe transferring data between a Win 7 box (with source data on SATA3 external storage) to a Synology NAS DS1511+. The below are a couple of simple screen grabs taking about half an hour into transferring a full back-up using Synology DataReplicator 3. The Win7 machine and NAS are connected via gigabit ethernet to the same router. No jumbo frames or trunking.
Fig 1. DSM 4.1 monitoring during backup
Fig 2. Windows 7 monitoring during backup.
I found that enabling jumbo frames on my Win7 machine killed any connection to the NAS, despite the NAS having jumbo frames enabled. I think (but haven't confirmed) that the router doesn't support jumbo frames, and therefore may be the cause of the issue. Having said that, it's not clear how much additional performance you could milk out of such a configuration.
The DSM Resource Monitor sampling frequency appears lower than the Windows monitor which may go some of the way to explaining why it looks a little more choppy as seen from the NAS. Nevertheless, sustained transfers seem to average about 80MB/s which will get through most home network transfers pretty quickly. I have noticed on some lengthier transfers that throughput can (infrequently) drop off markedly for a time before returning to about 80MB/s but haven't investigated why this occurs.
From what I'm reading, you need to enable jumbo frames on both the computer and the NAS, then set them to use the same MTU size-- that might fix the killed connection issue, but could result in further issues when your win7 machine and your router can't talk any more...
ReplyDeleteAll links in the chain need to support jumbo frames, including the end points and any network elements in between. It turns out that my router doesn't have a configurable MTU size for the LAN ports, only out onto the WAN (DSL/Cable) link. The NAS and PC both had matching MTU settings >1500 in my simple test mentioned in the original post.
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