Faster USB 3.0 Performance: Examining UASP And Turbo Mode

Page 3 - Seeking answers? Join the Tom's Hardware community: where nearly two million members share solutions and discuss the latest tech.
Not open for further replies.


Feb 10, 2015
264MB/s~270MB/s is Sata3Gbps Here, USB3.0 is working like Sata-II 3Gbps, not 5Gbps. Nec Renesas 700,
USB2.0 480Mbits in theory is 60MB/s but I never seen go beyond 45MB/s, usually around 35MB/s.
Sata-III 6Gbps is a paradox because the Sata-III controller is usually connected to a pcie x1 lane "5Gbps."


Dec 28, 2009
I have a notebook (MSI FX603) with the USB 3.0 NEC/Renasas chip, and it's dirt slow during backups, even with WinPE media, seldom goes above the 350Mb mark, which is lower than USB 2.0 speeds. In fact, I can image my Dell XPS 8700 through the USB 2.0 port faster than with the MSI on USB 3.0. That's a crying shame, and not much we can do about it.

It's not like we can totally uninstall all of the NEC software in Safe Mode, reboot & install the Intel USB eXtensible USB 3.0 controller, it won't happen because of the NEC chip. If I could, would love to, but can't.

The only time the NEC chip had any speed (and throughout this, there's been SSD's installed), was when Windows 8.1 was on the computer, there was a driver that sped it up much greater than stock, but still not surpassing USB 2.0's max. On good days, 500Mb/sec backup speeds.

Not much we can do, because in early 2011, USB 3.0 was still in it's infancy, like USB 3.1 is now, and I doubt that will double USB 3.0 speeds, let alone come close to 10Gbps/sec. I just 'don't get' these measurements, USB is a standard, like SATA, at least we know where we stand with SATA, depending on version, we know what to expect, based on the drive installed. JUst that no matter what, SATA-1 will never sustain 150Mb/sec, I don't care if a Samsung 850 Pro is installed, may hit it at peaks, the average will be 135-140MB/sec. With SATA-2, it drops further, to 250-260MB/sec (out of 300MB/sec max) & with SATA-3 & current for most, about 520-540MB/sec max (out of 600MB/sec max). Other than RAID setups, no one reaches 600MB/sec, though some reads comes close at peaks. So with the best SSD's, 520-540MB/sec average is decent speeds, there are lower quality SSD's that has much less write speeds, dragging a few down to almost SATA-2 max speeds. You get what you pay for, and there's a few really decent 120-128GB choices for less than $100, it's the sub-$60 models that doesn't get the job done.

Yet back to the point, I don't believe it the enclosure's fault that UASP isn't getting the job done, when others are bragging about the same model, it's the generation of the USB ports (early versions were more of an experiment) that's the problem. Most newer stuff runs backups fast with USB 3.0. That is, as long as NEC/Renasas is not involved. I'd never purchase another computer with that brand of USB 3.0 chipset, and there's ways to find out about these things prior to purchase. For example, a downloaded spec manual provides a lot of details.

Sorry I can't help those with NEC/Renasas USB 3.0 chips, have searched for 3 years & have yet to come up with an answer. Should I do, will be the first to post back here.



Oct 29, 2015
What the hell?! USB 2.0 does *not* use 8b/10b encoding.
How can I even try to read this as a "professional" article if it's wrong right from the get go...
Not open for further replies.