Beware: Atom330 Performance Woes

[luangm1]

Hi all,

 

I'm new to Unraid and just finished setting up and moving files to an unraid server (4.7 Final) running on Atom330 and 2GB of RAM. The justification was to build an ultra low-power file server that runs 24x7 to replace my ageing WHS (which ran on this setup before I decided to move).

 

I precleared 2 data disks with no errors.

- 1.5TB WD Green. Took ~28 hrs.

- 2TB Seagate Green. Took ~30 hrs.

 

I mounted another NTFS drive with WHS data directly and moved files to Unraid data drives.

The problem is that the average speed was only ~20 MB/s, even for large file.

Copy files from network is also about the same speed.

 

Initially I thought it was the slow performance of Unraid, as I was expecting at least 50MB/s for the green drives on large ISO files. In WHS I can easily move ~50MB/s. (Same Motherboard, CPU, RAM etc.)

But from reading all the reviews It seems Unraid should not be this slow.

 

So I did another experiment, Dual booted into Server 2008 R2 in the same machine and used YAReG 1.0 to copy from ReiserFS to another drive. The preformance was about 10~15MB/s.

In all two cases the CPU is only ~25% loaded, only ~1GB ram is used.

 

 

In a final test, I moved a ReiserFS drive into my workstation (Dual Xeon E5520, 12GB ram, SSD etc.), and used the same YAReG 1.0 to copy files out. The Performance was easily 50 MB/s+.

 

So, the conclusion based on the above experience seems that ReiserFS doesn't play well on Atom architecture. The CPU cannot be used efficiently and was the bottleneck.

This kinda blows my plan of using Atom 330 as a energy efficient fileserver.

 

Summary:

Case 1 - Atom 330, Unraid, Local copy from NTFS to ReiserFS. 10~20 MB/s, 25% CPU Load

Case 2 - Atom 330, Server 2008R2, Local copy from ReiserFS to NTFS. 10~15 MB/s, 25% CPU Load

Case 3 - Atom 330, Server 2008R2, Local copy from NTFS to NTFS. ~50 MB/s, 10% CPU Load

Case 4 - Dual Xeon E5520, Server 2008R2, Local copy from ReiserFS to NTFS. 50+ MB/s, negligible CPU load

 

Conslusion:

Atom 330 is NOT RECOMMENDED for unraid setup due to the slow file operations. CPU only used ~25% (remember it's a dual core with hyper-threading).

 

Anyone else can confirm this conclusion or is there anything I can tweak?

[WeeboTech]

What motherboard is the Atom 330?

 

~20MB/s to a parity protected isn't all that slow without tuning. Although it should be at least 25MB/s-32MB/s

 

unRAID does not use allot of CPU, hence 25% cpu for moving files is not all that much.

 

I had an Abit AB9 Pro with a 2.6Ghz core 2 Duo and I was getting 10-15MB/s with the older distro's before tuning.

 

I suppose you could try testing to a cache drive or turning off parity to prove/disprove the parity calc speed's involvement.

 

When you do these copies is it from drive to drive or is it over the network?

 

 

 

[Johnm]

I'll contradict you.

 

I was using an asus Atom 330 ION board for a test server. I was getting 80MB/s across the wire to a cache drive, 25-35MB/s directly to the array.

I switched that to a supermicro atom 525 and the performance is exactly the same (so does my xeon e3-1240 now that i think about it)..

 

In win 2008 on the same board, I also got full drive speed or wire speed with SSD's. It is the parity protection unraid that is the bottleneck. that takes almost no CPU resources to calculate. That's why you see better performance in WHS (WHS v1 is horrid for network speeds btw), there was no realtime protection. The drives you use and how full they are will also effect the speeds too.

Many users  are running Atoms and have no issues. I love mine..

 

However i will agree that preclears on an atom with a low amount of ram WILL take a little longer to preclear.

bumping up the ram speeds that up. bumping up the CPU and RAM (a different board) makes it even faster... but not by much, just a few hours tops.

 

 

I'll ask what board also?

[luangm1]

Thanks for the reply guys,

 

I mentioned earlier I did NOT put in a parity drive YET.

Unless somehow Unraid calculates parity anyways and discard them, which I doubt is the case.

Just straight copy. I was hoping the build the parity later.

 

Motherboard is the Zotac IONITX-F-E.

 

Now I'm wondering if I set up something wrong.

I did format the drives to be 4k-aligned even though they are not AF drives.

Could this be the issue?

 

For both drives Preclear time breaks down like this (approx.):

~5 hrs pre-read @ 80-100 MB/s

~5 hrs zeroing @ 80-100 MB/s

~20 hrs post-read @ 20~30 MB/s

 

the post-read speed looks really suspecious. Any ideas why?

 

Also like to mention, when I copy files, I copy them from \\tower\sdd1 (mounted and shared NTFS partition) to \\tower\share.

(because I don't know how to use linux cp command yet  . )

Using top command shows the SMB process takes about 25-50% CPU, could this be bottlenecking?

 

Network is not the issue, my entire network is GbE.

ifconfig eth0 shows the speed to be 1000 mbps.

 

Thanks!

 

[Johnm]

What kind of drives?

 

post a syslog.

[WeeboTech]

20hrs post read 20-30MB/s is suspicious. Something else is going on.

 

post the syslog, let's see what the drivers say.

[dave_m]

Also like to mention, when I copy files, I copy them from \\tower\sdd1 (mounted and shared NTFS partition) to \\tower\share.

(because I don't know how to use linux cp command yet  . )

 

I'm not quite sure what you mean here.  Are you saying you are using windows explorer on your local PC to copy data from one unraid drive to another?  I wouldn't expect very good performance for that scenario, even on gigabit ethernet.

 

The total time to preclear the drives sounds about right, even though the reported speed on the final step seems slow.