What data transfer rate should I expect from a NAS?

[shankarcams]

I have a Seagate Blackarmor 220 NAS with RAID enabled. I find it EXTREMELY slow in all its operations, be it read, write or even simply opening its own web page.

For example, it takes 30 minutes to copy a 7GB file across a 1GBPS network in single process mode. Would anyone be able to tell me whether this is all I can expect from a NAS or whether this is particularly bad.

Regards,

V Shankar

 

[bobbyprajan]

Are you transferring a single file or 7 GB or several small files ?

If you are transferring a single file, the speed is somewhat low. I am using a buffalo router as nas with a WD 500 GB usb drive and my speeds are about 7 MBps for big files over 1 Gbps ethernet while doing an smb transfer.

A dedicated NAS should do better.

 

[dazoy]

How are you copying the file?

Is it ftp or SMB share or NFS? Are you using wireless or wired network? Is there a hub or switch in between the two? There are too many variables. Could you provide more details about your setup?

I get about 40-50 MBPS from my synology NAS over sftp on a wired network.

Cheers,

Saurabh

 

[kumarab]

That is terribly slow actually, but the transfer speeds will depend on a lot of other factors;

1) It will never be above the slowest element of your connection--so if you're reading from/writing to a 5200rpm HDD, the overall transfer rate won't go over 20-25MBps no matter what..around 50-60 for 7200rpm HDDs.

3) Cabling--Make sure you're using Cat6

Otherwise, as I said..you should be looking at achieving atleast 20MBps transfer speeds with your setup. So, a little less than 6 minutes for that 7GB file. Something is definitely wrong, but I can't say anything more before knowing more about your whole setup.

 

[dazoy]

That is terribly slow actually, but the transfer speeds will depend on a lot of other factors;

1) It will never be above the slowest element of your connection--so if you're reading from/writing to a 5200rpm HDD, the overall transfer rate won't go over 20-25MBps no matter what..around 50-60 for 7200rpm HDDs.

I think the speed should still be faster as the OP is using RAID and not a single disk.

3) Cabling--Make sure you're using Cat6

CAT5 is still certified for 100 mbps, which is much faster than the transefer rate.

3)Otherwise, as I said..you should be looking at achieving atleast 20MBps transfer speeds with your setup. So, a little less than 6 minutes for that 7GB file. Something is definitely wrong, but I can't say anything more before knowing more about your whole setup.

I think a good point to check would be if cache is enabled on the disk, or if there is any data transfer limit imposed by the NAS.

Cheers,

Saurabh

 

[shankarcams]

Thanks everyone for the initial responses. My objective is to decide whether it is the NAS box that is at fault in which case I need to replace it with something else.

Here are answers to questions by various posters:
1. Single file. Several files are processed sequentially unless I explicitly open several sessions. Several sessions seems to degrade, even in read mode when the mirroring is actually supposed to help.
2. All wired connection. Cat5 (though as someone pointed out, the CAT5 speed limit is far higher than actual speeds achieved). (On WiFi takes HOURS to copy a 7GB file).
3. There is a Cisco 1GB switch in between, though that does not seem to affect PC to PC transfer rates. It is only NAS to PC that is affected.
4. Using 5200RPM disks as the enclosure is small and want to reduce heat buildup.
5. Copying using NFS.

If I did wish to replace the device, what is a high performance NAS with RAID and DLNA server support?

Regards,

 

[kumarab]

@dazoy
* "Slowest element"..what's he writing to?
* 100Mbps is 12.5MBps of a theoretical maximum, much lesser in real world, stables out at around 8-8.5 for most people.

Other than that, yes..as I already mentioned, he is still getting terribly slow speeds..and that should be looked into.

 

[kumarab]

@shankar

Thanks for the details--

*This seems to suggest an FTP process--you should look deeper into the seetings

*Atleast get Cat5e, if not Cat6. On a Cat5 cable..your 7GB file will take around 15 minutes under ideal conditions anyway. Still less than your 30 minutes, but it is a bottleneck nonetheless.

*You should check the Cisco manual--there is a difference between supporting a bandwidth 10/100/1000 and being "certified" for it.

*As I said, those limit you to a 20-25 MBps real world speeds anyway. Also, although you haven't specified..if you're using RAID0, then expect to see double speeds when writing to /reading from the HDD IN the Raid config.

*Lastly--Again, it all depends on the slowest element. If you're reading from your RAID'ed drives but writing to a 5200rpm drive on your PC..you'll still get a maximum of 20-25MBps. If a Cat5 cable is used, don't expect to see anything more than an average of 8.5MBps..so on and so forth.

 

[bobbyprajan]

3. There is a Cisco 1GB switch in between, though that does not seem to affect PC to PC transfer rates. It is only NAS to PC that is affected.

Can you check the speed/duplex settings of the port in your cisco switch where the NAS is connected ? Both the switch port and NAS port settings should match. Also check the cisco switch logs to see if there is any error messages for the port where NAS is connected

 

[dazoy]

@dazoy
* "Slowest element"..what's he writing to?
* 100Mbps is 12.5MBps of a theoretical maximum, much lesser in real world, stables out at around 8-8.5 for most people.

Other than that, yes..as I already mentioned, he is still getting terribly slow speeds..and that should be looked into.

I did not quite catch your comment about slowest element above. Is that a question to me??

 

[bobbyprajan]

I did not quite catch your comment about slowest element above. Is that a question to me??

Guess he is talking about the destination to which the file is copied

>>3. There is a Cisco 1GB switch in between, though that does not seem to affect PC to PC transfer rates. It is only NAS to PC that is affected.

From the above statement, the destination of the copy is the PC internal hard disk and it cannot be a limiting factor.

 

[vprasad84]

Hi,

copy large size single file (not small sized many files) from your PC to NAS & then try to see the transfer rate from your task manager or the copy window (assuming you have Microsoft Windows OS see below images)





To see at what speed it is getting transferred... e.g if it is showing 10% on your 1Gbps connection then it is getting transferred at rate of 100 Mbps...5% would be 50Mbps & so on...referring second image & considering 1Gbps connection, you should get transfer rate of above 25MB/sec only so accordingly you can consider if performance is alrite & if you are getting transfer rate below 20-25MB/Sec then you need to workupon to improve.

If transfer rate is not sufficient i.e below 20MB/Sec, try enabling jumbo frame option in your NAS & your PC's Ethernet interface options (only if your Ethernet interface supports) & then retry with above steps to check the transfer rate

If still not successful then if you have RAID1, disable it from options or disconnect a single hard drive so other continues running & again retry with above steps to see if there is improvement in transfer rate after breaking the RAID. If it still fails then your hard drive seems to be having issues & you need to consider for replacement.

 

[shankarcams]

Thanks vprasad64 for the tip. I got a consistent 25% on the transfer rate and now it took only 5 minutes for the same file to be transferred. Something funny with such massive disparities in transfer speed, but at least I don't need to search for another NAS now.

I did try to enable Jumbo Frames on my Dell XPS with Broadcom Adapter, but the adapter does not seem to support jumbo frames (which is funny). Anyone have any idea what chipset is used by Broadcom for their Dell supply circa 2009? I will try to update the driver.

Regards,

 

[vprasad84]

mainly performance issues are seen in sata raid. It is ok for data safety but performance would not be much good in raid on sata drives. High performance is achieved with raid on sas drives of 15k rpm's speed on highend servers or san's so u get througput of 10gbps on it.

 

[haisaikat]

Reposting from one of my earlier threads, see if these readings from a NAS are of use to you

http://www.hifivision.com/media-str...ome-theater-video-streaming-3.html#post316750
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I order iBal cat6 cables from ebay and it arrived yesterday. Earlier my DNS323 NAS was connected to the Linksys WRT610N Router via a cat6 cable and also the laptop was also connected to the 5GHz Dlink bridge via another cat5 cable. I replaced both the cables with cat6 and ran some data transfer tests. Instead of trying to play the viseo I did normal file copy tests. Here are the test results

The file in question is the same 45GB m2ts file of Avatar movie (2D) kept in my NAS connected to Router directly. Please note that the speed slightly increases with smaller file sizes but since the intention of this test is to check full hd streaming so I do not want to post those results


1. Laptop connecting over 2.4 GHz wifi N at the same place as bridge --> 2.4 to 3 mbps
2. Laptop connected to bridge via cat5 cable to bridge --> 5.8 to 6.2 mbps
3. Laptop connected to bridge via cat6 cable to bridge --> 7.1 to 7.5 mbps
4. Laptop connected to router via cat5 cable --> 14 mbps
5. Laptop connected to router via cat6 cable --> 15 mbps
6. Laptop connected to NAS directly via cat5 cable --> 16 mbps
7. Laptop connected to NAS directly via cat6 cable --> 17 mbps
8. Laptop connected to wifi N 2.4 GHz network just beside the router --> 3.7 mbps

Needless to say that the streaming playback of this file worked well only in 4,5,6,7 only but the desired scenarios (1,2,3) did not happen properly since as per the file size at least 8 to 9 mbps file read throughput would have been required which this architecture falls short of.

A couple of other observations the channel width of the 5GHz band was set at 40 but changing the setting to Auto (20 or 40) improved the throughput (above readings are based on that). Setting jumbo frame options (different sizes) in NAS degraded the performance. Tweaking the Fragmentation Threshold, BEacon interval, etc parameters in the router degarded the throighpur hence kept them at default values.

 

[sam9s]

I might be a bit late on this thread .... posting after couple of months, out of india right now so participation is bare minimum these days .....

@shankar you might want to check out my below post that I made in my NAS thread. its a DIY NAS.

USB 3.0 is understandable, however let me also share some technical facts. NAS 98% of activities is done via Network. In practicality once it is up and running you wont even know it exists as it would just lay somewhere in the corner. Copying of data, shuffling of data, installing plugins, maintaining shares every thing is done via Network, so instead of investing on USB 3.0 (mobo or PCIe card) invest or plan your LAN to make it quality. Trust me with proper 1Gbps LAN, and AHCI enabled, transfer speed (practical ofcourse not theoretical) competes USB 3.0.
My USB 3.0 speed vary between 90MBps-150MBps (depending on the type of files being copied, HDD buffer etc), and on my 1Gbps network when I copy my data on my Unraid, My speed vary between 50 MBps to 75MBps easily, which is very very good. Not all people manage to get that speeds over LAN, reason.... quality 1Gbps network cards, Quality Cat 6 cables and Quality router (Linksys E2000) and Unraid on AHCI. Check out few snapshots to make it believable ...

You can see its been copied to \\SamTower (network drive)which is my Unraid.

Here USB 3 speed.

thread .. is my NAS thread in my signature ......

 

[Shivam]

NAS is not the fastest way to transfer data. It will not be as fast as a direct SATA III or even a SATA II connection.

I was able to slightly increase the speed of data transfer by switching off the not needed services, data journaling and downgrading the firmware of my Netgear ReadyNAS.

 

[shankarcams]

As my closing out post, here is an update.

I bought a Synology DS712+. I ran the Intel NAS Speed Toolkit on both the boxes (my old Seagate Blackarmor and the new Synology). The Synology BLEW ME AWAY with its performance. The performance was between 6x to 10x of the performance of the Seagate.

I guess my decision is clear!