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The Graveyard - Products No Longer Supported => D-Link Storage => DNS-323 => Topic started by: BigShooter1974 on May 11, 2008, 01:34:57 AM

Title: Upload/Download Speeds
Post by: BigShooter1974 on May 11, 2008, 01:34:57 AM
Someone tell me if this is normal please. 

The Situation:
My PC's all run Windows Vista x64 or Windows XP Pro x86.  They have all used the D-link drive mapping software to map the appropriate drives.  My DNS-323 is connected via the Gbit ports on my DGL-4300 using all Cat6 grade cables.  All my PC's are using Gbit ethernet cards with updated drivers.  My DNS-323 is running firmware 1.04 and is running in a mirrored raid 1 array. 

The Problem:
It doesn't seem to matter if I am uploading or downloading, but my best transfer rates are somewhere in the area of 12MB/s.  Is this normal or am I doing the math wrong?  Even using FTP across my LAN the rates are almost identical.  I have no issues with the DNS-323 functionality at all.  Everything seems to work fine and has for over a year.  It just seems slow for something using a Gbit connection.  Ive tried different Gbit ports on 2 computers and the result was the same.
Title: Re: Upload/Download Speeds
Post by: fordem on May 11, 2008, 08:03:45 AM
Is this normal or am I doing the math wrong?

Where do I start - I guess by saying that you haven't provided us with enough information to determine that.

What's normal for you might be abnormal for me - and depending on what I'm doing - I can report speeds ranging from 2GB in a shade over 2 minutes to 10GB in around 15 hours - and that's from the same machine, and it's running XP Pro x86, a Broadcom based gigabit NIC, CAT5e cables and gigabit ports on a Netgear switch.

The first thing you need to consider is the speed of the disk subsystem in the PC (including fragmentation), and the second thing you need to consider is the perhaps "nature" of the data - transferring a single 10GB file is going to be a lot quicker than transferring 10GBs worth of 3MB files.

D-link claims speeds (if I recall correctly) up to around 23MB/s and I believe it can deliver that, provided the otherside can handle it - my best has been around 21MB/s.

I understand the new firmware (1.05) which may be released within a week or two will include support for Jumbo frame - so - if your network can handle Jumbo frame, and your end points can accomodate the data transfer - that would be a predicted increase of as much as 30%, so you're theoretically good for something approaching 30MB/s.

Where I believe your problem may originate is in your expectation of gigabit networking - it may not be as fast as you think it should.

Back in the days of 10 mbps networks, when 3Com introduced their first "parallel tasking" cards they sold a kit which included instructions on how to benchmark network speeds and what I learned was that the average 10 mbps card would/could only deliver around 2~3 mbps - the 3Com cards were good for a lot more, and I did get one up to an amazing 11mbps (by hammering it from three systems simultaneously).

When fast ethernet first came out the best I could achieve was 20~30 mbps (on shared media ie. a hub), switched networks are now common, and I assume the 100 mps technology has matured and I have clocked as much as 98 mbps.

In similar fashion many gigabit cards don't deliver anywhere close to gigabit speeds - you mentioned using gigabit cards with updated drivers - I'll ask whose updated drivers - having used gigabit cards with a popular chipset and clocking 65~70 mbps with Microsoft's "updated" drivers and being able to double that with the older OEM drivers that were supplied with the card.

Have you measured throughput between the PCs themselves ?  What sort of speeds have you seen?

From the same system mentioned above going to an IBM xSeries server, W2K3, Intel PRO/1000 NIC - I can hit 330 mbps - so it's fairly safe to say that the limitation in my tests above was the DNS-323
Title: Re: Upload/Download Speeds
Post by: BigShooter1974 on May 11, 2008, 12:17:16 PM
as far as drivers up to date, all my drivers were pulled from their respective chipset manufacturers where possible.  The chipset in my primary machine is a realtek RTL8169/8110 chipset as well as a Yukon 88E8056.  Neither yeild any great improvement over the other.  And neither are spectacular in their own right I'll admit, but are capable of far greater speeds than the DNS-323 is providing.  I see the same transfer speeds across my network as you do.  That is to say, in the 300mbps market with bursts upward of 350.  I'm not lookign for miracle speeds or anything.  Frankly i'd be satisfied with the 21MB/s that you say you are getting to the DNS-323.  Yesterday I tried reformatting again, moving all my data off the DNS-323 to a local raid array on this machine which uses WD raptor drives.  I moved them in sections based on the data type.  My 21000 MP3s took approximately 3 hours to download to this PC and about 4.5 hours to upload back.  The uploading cracked along at a brisk 2-9MB/s.  Staggaring speeds I know.   Not to mention all my backup data from my various machines and bulk files I had stored.  Since most of my machines run a variation of raid arrays perhaps this is also contributing to the bottleneck.  Maybe I'll buildup a new machine with a single SATA2 drive and see if that makes any difference.  But I don't expect it would be terribly significant.  I'm really not sure what to do anymore. While I dont move my files around terribly much, I do on occasion like to cleanup or transfer them to my laptop if im going out of town for example.  It would be spectacular if this process would not take a day to complete. 

Thanks for your reply, I'll hold out hope for 1.05 and Jumbo Frames since all my hardware is capable.  But perhaps its time I looked for a more advanced solution that will provide me with the performance I hoped my trusty DNS-323 would. 
Title: Re: Upload/Download Speeds
Post by: fordem on May 11, 2008, 01:30:13 PM
21000 MP3s is a lot of small files - it's going to take time any way you transfer it - how long does it take 'desk top' to "desk top'?

Small files have a "housekeeping" overhead in that the disk's head actuators must repeatedly move from the data storage area to the block allocation and directory areas and back.

If you look at my earlier post - I mentioned transferring a 2GB file in just over 2 minutes - that was a single test file created especially for the purpose - and 10GB taking over 15 hours - that was a collection of 145,000 files, stored in 10,000 folders - actually closer to 12GB.

By the way - that Reaktek chipset is the one I was referred to earlier - I would suggest using the driver provided by the motherboard manufacturer (if it's integrated), or the NIC manufacturer (if it's not) rather than the Realtek driver or the Microsoft one.

Now - if you pardon my going off on a tangent ...

A couple of years back, in a different forum, someone questioned the speed of his new gigabit network - I don't remember the actual numbers - but he has quite disappointed in the throughput he was getting and refused to accept my explanation on his disk subsystems being a possible bottleneck - he was using high powered desktops with RAID subsystems and would not hear a word against them - until he tried a simultaneous copy - and discovered that when running four simultaneous transfers from one system to four different systems, that one system could deliver data (read from the disks) almost four times faster than it could receive data (write to the disks).

RAID subsystems, especially RAID 4 and to a lesser extent RAID5, bottleneck on the writes - so you really do need to get a good idea on the read/write capabilities of your disk subsystems.