Speed of PCI Express x1 slots on my HP Elite.

[JerryDT37]

Hi! I recently installed a PCI express USB 3.0 controller into my HP Elite 460Z with a Foxconn motherboard H-RS880-uATX:1.02. PC Wizard says it's a "2a92" motherboard.

Here is a pic and some specs from HP.

Anyhow, the manual for the express card says installing the card in a PCIe 2.0 slot will allow the card to operate at 5Ghz, but that it will only operate at 2.5Ghz if in a PCIe1.0 slot.

In Device Manager, the ports for the card are operating at "high speed" as opposed to "super speed."

PC Wizard says the x1 slots on my PCI Express bus are version 2.0, but the link speed is 2.5gb/sec.

I am disappointed that my transfer rate to an external usb 3.0 device is only about twice as fast as when I have it in a usb 2.0.

Tried to find a motherboard manual for my motherboard to find out if my x1 slots are version 1.0 or 2.0, but can't seem to locate on HP or Foxconn's site.

Is there anyone out there that understands this well enough to tell me if I will ever be able to transfer faster than the 60mb/sec I am getting on my file copies?

[wb2001]

Your board is IMHO PCIE 2.0 mimimum, as the standard was impliemented 2 years prior to your board.

Try HD Tune v2.55 on your computer drives, and it may tell a different story.

[JerryDT37]

Ok I ran that utility.  It definitely shows a faster transfer rate than I'm getting with Windows copy.  I guess I still don't understand why my ports are running "high speed" instead of "super speed." 

 

[LarryMeBoy]

Jerry,

So you are getting max 108 megabytes per second which is 2.25 times the specified 48 megabytes of USB 2.0. I have a PCIexpress 1x eSata card that gets only half the transfer speed that my internal Sata gets. (54.7MBs or 547 megabits per second). Not much faster than USB 2.0. My internal SATA II WD Cavier Black is showing 108 megabytes per second max with HD Tune.  I also say whassup with the x1 slots? Maybe this is good as it gets.

Larry

[Big_Dave]

Hi Jerry,

What you are probably experiencing is the overall throughput rate.  The external hard drive is most likely the bottleneck due to the controller being used in the drive.  USB 3.0 and SATA III interfaces have theoretical speed ratings.  Here are some HD Tune measurements of a SATA III SSD using; motherboard SATA II port, eSATA port and finally a USB port on the same PC.

  31 MB/sec average using USB 2.0

113 MB/sec average via the motherboard SATA II port

118 MB/sec using an eSATA port (different motherboard chip)

All of the above measurements are a straight line with the SSD. So the throughput bottleneck for me using the SSD are the interfaces and not the external device.

Even using a SATA III rated SSD I am seeing less than theoretical maximum for a SATA I interface (150 MB/s). The same SSD on a SATA III motherboard will see about 300 MB/s.

[JerryDT37]

I can accept that my seagate goflex desk may be a bottleneck in the process.  What I don't understand is why my pci express version 2.0 slots are showing high speed instead of superspeed.  ????

[LarryMeBoy · Accepted solution]

PCIe 2.0 has the ability to clock the link speed up and down depending on the actual speed of the attached peripheral. http://www.10stripe.com/featured/quick/pci-express-2-0.php I use HWinfo32.exe and it is showing the chipset as capable of 5gbs, but my periperal limits it to 2.5gbs

.

[Big_Dave]

Jerry,

Check with the board manufacturer to see that you have the correct drivers. That might explain the difference between superspeed (USB 3.0) and highspeed (USB 2.0).

PC Wizard is showing GHz which is the signaling rate of the bus.  PCI-E 1x is 250 MB/s in each direction.  PCI-E x16 is 16x250 or 4 GB/s.  These are theoretical transfer rates. In reality, the actual throughput will be limited by overhead, design efficiency and by the size of the data object.

[JerryDT37]

Larry,

As I don't have any other usb 3.0 peripherals, and hwinfo32 shows the same thing on my pc, I am going to quit fretting about it and assume you are right.  If anyone ever happens upon this topic and has updated insight, please post here, as I will continue to watch this thread, thanks!