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[bkspero]

I have owned a DIR-825 for a few months, but only just upgraded all the LAN cable to Cat 6.  I now need help because, while I get lights showing gigabit connections to the computers, the actual transfer speeds are only about 10 to 60 Megabits/second (1 to 6 Megabytes/second).  I didn't expect 1000 megabits/second, but I am only getting 3% of that speed.

Cables are all new Cat 6 with the factory connectors on both ends.  Router is functioning as a DHCP server.  Other than the WLAN settings (which should not affect the wired connections), the router is using default settings.  No other computers are using the network during the transfer tests.

Router is Rev A1 with 1.12 firmware.

I am measuring the speeds by transferring groups of 100 to 150 megabyte files that total between 1.5 gigabytes and 6.4 gigabytes per transfer.  I measure the transfer time using a stopwatch.  There is little and no consistent difference in the transfer rate due to the different sizes of the transfers.

All transfers are thru the LAN ports (not WAN or WLAN).

This can't be normal, is it?  Please help?  For more details, see below.

Barry



Devices are: 1) a new Mac Mini, 2) a 2008 vintage Mac Pro, 3) an old homemade PC with a 1.4 GHz Athlon processor and a gigabit network card, 4) an HP Pavilion dv9700 media laptop (dual core AMD 64 bit 2GHz processor), and 5) a Lacie Ethernet Mini NAS drive.  All with gigabit ethernet connections and for those with wireless, the WLAN was off.  All have current software and drivers.

The NAS drive and the old PC both connect directly to the DIR-825.  The others connect via a Dlink DGS-2205 gigabit switch.  I have, however, done a few tests in which the switch was bypassed and all connections were directly to the router, and there was no improvement in speed.

Also connected by Cat 6 cable to the DIR-825 is a Linksys 310N wireless router (serving the other end of the property).  Also connected to the DGS-2205 switch are both another computer with 100 Mb/s ethernet and a Netgear 614 G router (100 megabits/sec ethernet).  Both the Linksys and Netgear routers are operating as wireless access points only (their DHCP servers are turned off).    All gigabit connections on the DIR-825 and DGS-2205 switch show lights indicating gigabit operation.  For one of the tests, I physically disconnected all 100 MB/s devices so there were only gigabit devices on the LAN.  No improvement.  All cable runs are 100 ft long or less.

What have I missed?

[claykin]

Well, for one you did NOT need CAT6 cables.  CAT6 at under 150 feet run length does nothing for you as compared to CAT5e.

Moving on.....  If things are working well you should expect to see about 400-500Mb/s or 50-62.5MB/s throughout with Gigabit.  Your older PC's with gigabit cards on the PCI bus likely won't ever reach 50MB/s.  Also, your LaCie NAS is also likely an Achilles heel in the setup as its probably not capable of coming close to saturate gigabit.  I would try a setup with 2 x relatively newer PC's (something 2007 or newer) and make sure the NIC settings on both are set to gigabit/full duplex.  Make sure you have the latest driver from the card manufacturer.  Also, if it has a setting to enable Jumbo Frames enable it and try 7K or 9K jumbo frames, but before you do so, check to see if your Dlink switch supports Jumbo Frames.  The DIR-825 does.  You should see a significant improvement.

 

[bkspero]

Thanks for the input, Clay.

I understand that I did not need to install Cat 6, but for the modest added cost it gives me an safety extra margin of bandwidth potential.

As for the computers, three of the computers which I have used for the test are 2008 vintage or newer.  The MacPro (2008 8 core), the Mac Mini (2009), and the Pavilion dv9700z laptop (2008).  I have done binary tests with all combinations of these, and all give results in the range of 1 megabyte/sec to 6 megabyte/sec.  Even when both computers in the test were wired directly to the DIR-825 (without connection thru the switch).  All are running in full duplex gigabit with the newest drivers.

I do not know the frame size.  If I can change frame sizes, and if they are smaller than 7k-9k, I will increase them and test again with direct connection to the DIR-825.  I do not know if the switch can handle jumbo frames.  I will check on that as well.  Do you think that changing to jumbo frames will give me a 20x jump in speeds from ca. 3 Megabits/sec to 50-60 megabits/sec?  Or even 10x to 30 megabits/sec?

Thanks, again, Barry

[claykin]

JF will help with large file sizes, but will not give you the huge improvement you are looking for.

Have you checked LAN - LAN file transfers between two PC's by going through your Gigabit switch only (no DIR-825 in the loop)?

[bkspero]

As you predicted, going to Jumbo Frames did not give me a 10x boost in speed with the current LAN configuration.  I did find out that the slowest transfers (1 MB/sec) were the result of Vista.  I booted to the Windows 7 RC on the computer that gave the slowest transfers, and it brought speed up to the others at 4-6 MB/sec.  Increasing the frame size to 9K didn't change speeds materially (some went up slightly and some went down).

The switch does support Jumbo Frames.  I'll do the test you suggested without the router.  And do it both with and without jumbo frames to see if the problem is the router.

Barry