2.5" USB 3.0 Enclosure for SSD (400MB/s?)

[sethk]

I know I've seen reviews or technical articles before with benchmarks showing an external SSD breaking 400MB/s over USB 3.0. Doing some google searches I'm seeing some mixed results. I would love to hear from someone who has a bus powered external USB 3.0 2.5" enclosure that does an SSD like the Samsung 840 Pro justice. I need to run VMs on an external SSD, and they tend to be highly limited by storage performance. There's only so much I can fit on the laptop's SSD.

 

[hotcrandel]

I've found that its more dependent on the USB 3.0 controller than the enclosure. If you're using an USB 3.0 controller made by ASmedia you're probably not going to have great speeds.

My roommate bought a $30 usb 3.0 case and put a 256GB Crucial M4 SSD in it, and has excellent speeds with his retina MBP. (As far as I can tell, the bottleneck is the SSD)

I've got an M4 in a usb 2.0 enclosure and you can run a few VM's on it just fine, the through-put is lower but the latency is much much better. This enclosure also has ESATA and works pretty well (200MB/s+ reads, over 100MB/s writes) with an intel port on my desktop.

 

[omniscence]

You might want to look into UAS (USB attached SCSI) and whether your host controller and device controller support it. It is required for highest speeds and also significantly increases random access rates.

 

[sethk]

Thanks for the tips. I have 2 USB 3.0 ports driven directly off the Intel x77 chipset (not sure if it's a H77 or a U77 - it's an intel Ultrabook). It's not an ASMEDIA add-on, these are intel-driven ports (Ivy bridge chipset). As far as I know, the chipset is capable of UAS, now I want to make sure the enclosure I pick is not the limiting factor. Anyone with first hand experience?

 

[defaultluser]

It's quite complicated to get UASP working, as the feature is still cutting-edge: you need OS, controller AND device support! Although z77 has native support for UASP, it's up to the motherboard manufacturers to actually IMPLEMENT it, so you will have to check your board specs. Also, you will need Windows 8:

The native Intel USB3 UASP solution is only supported under Windows 8. To further complicate matters, not all Z77 motherboards support USB3 UASP. A license is required to implement UASP, and not all motherboard manufacturers are prepared to pass on the extra cost of this license to the end user. This is a great pity, as USB3 UASP certainly provides a means to get the very best performance out of an HDD, and especially an SSD when connected via USB3.

http://www.myce.com/review/beyond-usb3-with-uasp-67035/Introduction-1/

 

[sethk]

Thanks for the feedback guys. I did some more digging, and I see that the native Microsoft USB 3.0 drivers in Windows 8 support UASP, if the device supports it. It looks like specialized drivers are needed for Windows 7.
MSDN link

Which brings me back to the question of a portable enclosure with UASP / SATA 6Gbit support for max speed. Some of the older articles used the Thermaltake BlacX, which of course uses an Asmedia SATA-USB3 bridge chip. Doing some more digging, I found a couple of other enclosures that also support UASP, and I think I will be ordering one from Amazon or the 'egg.

My goal again, is to have maximum performance running a Hyper-V VM from an ultrabook. I will post back with results.

 

[UhClem]

Resist the temptation to go for an enclosure that supports both USB3 and eSata. There is a possibility that your USB3 (with [and w/o] UASP) performance might be limited by the addition of the data multiplexing chip needed to support the dual interface.

 

[mwroobel]

Another thing to keep in mind is that just because the underlying chipset CAN support any particular functionality is no guarantee that whatever specific implementation you possess of that chipset and/or driver ACTUALLY have implemented it. This has been a commonplace issue with SATA and SAS products, especially expander and multiplier products for some time but has also cropped up in other adapter products.

 

[sethk]

From what I've read, UASP is not a hardware level feature to be enabled on the host (motherboard) chipset. It's a protocol level feature enabled by the driver. Since W7 did not support it natively, ASUS and some other companies enabled the feature themselves in proprietary drivers, usually licensed from other companies. In W8, it should just work on any motherboard that can use the native Microsoft USB3 driver - not chipset specific.

The limiting factor is the attached device, which must also speak 'UASP', and do so fast enough to make it worthwhile.