Ultra 4 Transfer speed very slow.

WiFi speed depends a lot on the distance, walls, etc and how much radio activity (interference). Link speed is very deceptive. In any event, you are certainly not limited by the NAS performance on your wifi connection. You can try changing channels, or even switch to 2.4 ghz band. inSSIDer is a good tool for looking at competing WiFi activity, though it will not show you interference from other stuff (microwaves, bluetooth, etc).

Also, it seems unlikely that you were getting 15 MB/s with your 108 mb/s router, as Super-G (and its cousins) has a theoretical limit of about 60 mb/s throughput, and is usually less. That would be 7-8 MB/s tops. Perhaps there is caching going on in the PC?

On the wired connection - are you using a desktop PC or a laptop? What NIC card? Also, you should be using CAT-5e or CAT-6, not CAT5.

when I did the test with wifi there were no other devices connected and the router was beside the computer just for testing.

here are some test I did with wired no router.
PC -> MBP speed about 70 to 90 MB/s
PC -> NAS speed about 40 to 50 MB/s

And wifi. tested with my MBP because the MBP have much better wifi card than my desktop pc and the desktop pc is using old 54Mb/s wifi card.
MBP -> Router -> NAS speed about 8 to 10 MB/s (5G Hz Band)
MBP -> Router -> NAS speed about 2.50 to 2.70 MB/s (2.4 GHz band)

I believe the WiFi 5 Ghz throughput, since 802.11n is similar in speed to 100 mbit ethernet.

50 MB/s or so is about correct for PC->NAS, you should get higher speeds on NAS->PC.

The speed is still to slow.

My nas is connected with 2 cat-5e cables to the router with 1Gbps connection
and if I connect a computer to the router with a cabal with 1Gbps connection
I only get about 47MB/s and 47 MB/s is 376 Mbps and that is not 1 Gbps so that is very slow.
And I get the same speed when I connect directly to the NAS with out any routers nor switch
1 Gbps is 128 MB/s.

And when I transfer BIG files throw wifi 5Ghz band and I have only 1 computer using that band with
I get the speed about 10MB/s and that is to slow
10 MB(s and that is about 80 Mbps

pls help me. and don't tell me I can't get any higher speed if so that I am foundering if the nas does not have any 1Gbps pan ports.

If you read this review: http://www.cnet.com/network-storage/net ... 013-2.html
You will see that they got 55 MB/s on writes. You are posting 47 MB/s which is pretty close. You should be getting faster speeds on NAS reads. Did you test that?

On WiFi you are getting normal throughput - I am not sure what you are expecting there, but 80 mbits/sec is a good speed for 802.11n @ 5 gHz Normally your WiFi thoughput is 1/2 to 1/3 the link speed.

I am using Netgear DGND4000 with 450 Mbps on the 5 Ghz band.
and I get much higher transfer speed when copying to another computer and both computers are connected via wifi
so how is it I get much lover transfer speed when the nas is connected with ethernet cable?
And why am I also getting much lower transfer speed when I connect to the nas directly with ethernet cabel?

With ethernet cable I get about 47MB/s and that is NOT 1Gbps
so why am I also getting lower speed with cable

When I copy file from the NAS to the computer a file size about 4GB the transfer speed via wifi is about 5 - 8 MB/s

-When writing to the ultra, you are limited by the speed of the ultra. It is not fast enough to keep up with 1 gigabit ethernet when writing to raid-5. Reads are faster, but still not quite up to gigabit speeds. The review I linked included measured speeds - you might read it.

-A 450 mbps link speed does not mean 450 mbps of throughput - WiFi doesn't work that way. The link speed depends on the the WiFi chipset in both the PC and router, and the signal strength on the path. The 5 gHz band has relatively short range - link speeds almost never reach the maximum possible. And throughput is 1/2 to 1/3 of the link speed. I have an R6300 with 1300 Mbps on the 5 gHz band, and still get 80-100 mbits of speed through most of my house.

-I suggested measuring read speeds on the ethernet network. The NAS is not limiting your performance over WiFi.

I have MacBook Pro late 2011
and I get higher speed when copying from the MBP to a PC and higer speed when reading from a PC to the MBP via WIFI.
And the signal strength on my MBP is about 90%.

And when I test the 2.4Ghz band with the 300Mbps link I get the speed about 2 MB/s and that is the same speed I get on my old Netgear Router DG834PN and that router only have 108Mbps on the "G" 2.4Ghz band
and I have set my new router on the 2.4Ghz band to use the "Up to 300Mbps" and my MBP comforts I have the 300Mbps band and I Know I can't get that speed. but why am I getting
same read and write speed as my old DG834PN router.

I believed that the DGND4000 should be faster with 2.4Ghz band than my old DG834PN router.

I just did a transfer test agen with a ethernet cable and the results are
PC to NAS about 25 MB/s
NAS to PC about 50 MB/s

Probably best to focus on one link at a time. I suggest gigabit ethernet.

Here's what I see posted:

PC->NAS 50 MB/s (test 1)
PC->NAS 47 MB/s (test 2?)
PC->NAS 25 MB/s (test 3)
NAS->PC 50 MB/s (test 3)

I haven't seen any MPB->NAS or NAS->MPB speeds for ethernet posted. SInce your PC test has a pretty broad range, you might want to try a couple more.

I am also unclear about whether you are using CIFS or AFP in the MBP.

How are you measuring the PC copy speed? Drag and Drop with a stop watch? Are you always transferring the same files?
Can you give us a bit more info on the PC? The OS, hard drive, the NIC card?
What firmware is installed in the ultra? What model disks? (WDC Red or green?)
Is everything directly attached to the router, or are you using ethernet switches as well?

Do you have jumbo frames enabled on the NAS or PC (not saying you should, just wanting to know).

BTW, your sig says NV+ v2. Do you have both, or is the sig incorrect?