ExpressCard 34/54, which?

Hey everybody, got a quick question. A friend of mine got a HDD enclosure that supports eSATA, and we're trying to figure out which eSATA Expresscard he should get. From some quick googling, it appears that the ExpressCard/54 is PCIex1, which does 250MB/sec, whereas ExpressCard/34 is simply USB 2.0, limited to 60MB/sec. Is this true? We are looking at the ExpressCard ones listed here:

http://www.newegg.com/Product/Produ...ion=eSATA&name=PC Cards / PCMCIA Add-on Cards

It is just one drive, so we dont neccessarily need to have two ports. Which one woudl have the better performance, the ExpressCard 34s or the 54s?

 

Well, 60MB/sec is at the upper limit of what hard drives transfer anyway, so it's not a huge deal. It's up to your friend, though. Either of them work, both would probably perform similarly with modern drives, but if you want a guarantee, go with the ExpressCard/54 model.

 

From what I read here, it appears they both have the same connection, the only different thing is the width. I'll just get the 34

http://www.synchrotech.com/support/faq-expresscard.html

 

expresscard is both usb 2.0 and PCIe 1x. Like you said, the difference is ony the width of the card. Just get the cheapest one. Also, bearin mind that a /34-card will leave 20 mm open, since it doesn't cover the entire slot.

 

Very good info. If you go to the bottom of the page there is a table that suggest expresscard 34 is 60MB/s max and 54 is 250MB/s each way. Also from my understanding of reading this article, expresscard 34 is USB 2.0. That's not good news because even though USB 2.0 has a theorectical max of 480Mbits/s = 60MB/s in practical terms the max sustained througput I've seen is about 35MB/s.

Check this chart and see how all usb 2 devices are at the bottom of the pile. The WD Mybook has three different interfaces with usb2.0, firewire400 & firewire800. See how usb 2.0 bottlenecks the performance badly.

http://tomshardware.co.uk/2006/12/05/storage-with-style-uk/page6.html

Go for expresscard 54.

 

according to http://www.expresscard.org/web/site/qa.jsp (the official website) and http://en.wikipedia.org/wiki/Expresscard there is no performance difference between 34 and 54.

 

Well that's good news. I just hope they don't implement usb instead of PCIe. It seems the manafacturer can use either.

 

Yup. What they'll probably do is use pci-e when they need more bandwith and usb when they don't and both when they'll need even more. I read in som thread that Belkins expresscard dock transfers video (and maybe audio) through the pci-e and the rest through usb