Silicon Power PC60 Portable SSD

I was worried that my review of the Silicon Power PC60 portable SSD could be anything more than the briefest of articles. Just a description and a report on speed. Easy. But it turned out that I was not able to reach the breakneck speeds this this USB-C 3.2, Gen 2 device is capable of.

Let me explain. ‘It is not you, it is me’. Or I should say it is not the Silicon Power PC60 its the computer you use it on.

Unless you have a computer that supports USB-C 3.2 Gen 2 (up to 10Gbps data transfer – almost full-duplex) or Thunderbolt 3 (up to 40Gbps full-duplex) then the only speed you will get is what your interface provides.

We explain all this in our USB, Thunderbolt and Power Delivery Guide for Dummies but here is a brief overview. (FD=Full Duplex or same speed both ways and HD=Half Duplex – it can only maintain around half the rated speed). USB speeds are

• 1.0 – up to 12Mbps (HD) – black keyed port and cable up to 5 metres
• 2.0 – 480Mbps (HD tops out at 280Mbps) – ditto
• 3.0 – 5Gbps (HD tops out at 3.2Gbps) – blue keyed port and cable to 3 metres
• 3.1 Gen 1, similar to 3.0 but FD using a dedicated .8m rated cable
• 3.2 Geb 2 – 10Gbps FD using a dedicated .3m rated cable
• Thunderbolt 3 – up to 40Gbps using a dedicated .3m cable

Note 1Mbps = .125MBps = .001Gbps or .000125GBps.

Rest assured that the Silicon Power PC60 will achieve 540/500MBps (4320/4000Mbps) with the right PC or Mac

Review: Silicon Power PC60 portable SSD

• International Website here.
• Price: A$167.90 – varies according to $AU vs $US exchange rate
• From: amazon.com.au
• Warranty: 3 years
• Country of Manufacture: Taiwan
• About: Silicon Power was founded in Taiwan in 2003 “by a group of enthusiastic data storage industry experts”. It now has four international branch offices and continues to specialise in various forms of solid-state storage.

About the Silicon Power PC60 portable SSD

The Silicon Power PC60 portable SSD is available in four sizes: 240GB, 480GB, 960GB and 1.92GB. The review sample was 960GB – 1TB in marketing terms. Big!

It is a nice flat package. Plastic square 80mm case, 11mm thick and 45g (59.4g with a cable). One corner has a lanyard slot. SSD is naturally shock-resistant.

It has a USB 3.2 Gen 2 interface and a dedicated USB-A to USB-C 30cm cable. If you use any other cable remember that most aftermarket ones are only USB 2.0 rated – these will not provide the rated speed.

It is pre-formatted in FAT32. That makes it compatible with everything. If, you’re definitely a Mac-only or a Windows-only person reformat it as Apple File System or NTFS to take advantage of the operating system’s advanced capabilities.

On the tech side, it uses the Silicon Motion DRAM-less SM2259XT controller and has a single 1TB 96-layer 3D TLC NAND Micron chip. The PC60 also uses a USB 3.1 to SATA converter with ASMedia’s ASM235CM bridge controller. So even though it is amazingly fast inside, once you hit the USB cable it tops out at 6Gbps SATA 6 speeds.

Testing the Silicon Power PC60

As is my wont, I eschewed speed test apps in favour of ad hoc, real-world-like tests. The reasons:

• Ultimate throughput depends on the computer USB interface. Do we know for certain that the computer isn’t the bottleneck? Using well-established speed tests implies a degree of comparability that is likely more misleading than useful.
• Not that I would ever suggest that any company would ever do this, but the more widely used a test is, the more tempting it might be for market participants to optimise their devices for just that test. Of course, that would never, ever happen.
• And, as I belatedly realised, the Windows copy dialogue can itself be a quite interesting record of how a file transfer proceeds.

I used three sets of data for my tests:

1. A single 3.72GB video file – which is getting close to the maximum able to be accommodated by a FAT32-formated storage device. This minimises interruptions for updating directory information.
2. A folder containing two subfolders and 78 large video files. It has a total size of 45.4GB.
3. A folder with lots of subfolders and many, many mostly small files. It has 123 subfolders and 1,880 files, amounting to 1.65GB in total.

The procedures was simple: Copy the file from computer SSD to the Silicon Power PC60, plugged in via USB 3.0. (See what I mean? None of my computers support USB 3.2 Gen 2.) Then copy it back again. Time it both ways and we’d have write and read speeds.

Problem was, my results initially made no sense. But in hindsight they were all to do with the USB interface – not the Silicon Power PC60.

Silicon Power PC60 and Mac

I thought I’d just use a current model Mac Mini for the test. SSD in the Mac, USB 3.0 rated connections, all ought to be fine. I copied the single 3.72GB file from the Mac to the Silicon Power PC60. Across it went in 14.75 seconds. That worked out at a nicely snappy 259MB/s write. Copying it back (read) took just a touch over 9 seconds, for 412MB/s.

Then it was time for the 45GB folder. That took nearly 37 minutes. Average speed: just 21.0MB/s. That’s what you’d expect with USB 2.0. Copying it back took less than two minutes, for a speed of 413MB/s.

Oh, I thought, maybe it was the FAT32 SSD format. That’s a relatively primitive Microsoft format. I reformatted to Apple File System and copied the 45.2GB folder over again to the Silicon Power PC60 SSD. It took 35 minutes and 36 seconds: 21.8MB/s. Just the slightest of differences.

Editors note: Damned old Mac! What it shows is that the drive is faster than the USB 2.0 interface.

Silicon Power PC60 and Windows

I started with the 3.72GB file to make sure everything was working fine. This ran very slightly faster than with the Mac: 14.11 seconds for a speed of 271MB/s. Copying back, the file flew from the Silicon Power PC60 to the SSD in the Windows computer in eight and a half seconds. That’s 449MB/s.

Then I copied the big folder. Several times. The time was between 17:49 and 20:35, or between 37.7MB/s and 43.5MB/s. The Windows copy dialog was instructive. Here are three screen shots of what was going on:

At times the copy was going fast – typically almost 300MB/s – and at other times slowly – usually around 19MB/s, sometimes as low as 5MB/s.

Was there something wrong with the Windows computer (and the Mac)? So I repeated with two other drives. One was an old 128GB SSD that used to be my desktop C: drive some years ago, which I’d popped into a USB 3.0 casing. The other was a fairly recent LaCie USB Type-C 1TB hard drive. Both ran much slower than the peak speed of the Silicon Power PC60, but were consistent throughout the copy for much snappier performance. The computer copied the large folder to the SSD in 4:42 and to the LaCie in 6:06.66 (ooh, spooky!). That is, they ran at 165MB/s and 127MB/s. Here are screenshots of the Windows copy dialogs for them:

Check, check and quadruple check

I spent a lot of time copying files and folders back and forth, trying to get a sense of what was going on. Copying from the PC60 to a computer was super fast. Copying large collections of data to it usually resulted in a pulsing pattern – although with a different arrangement of the pulses each time, as you can see from the screen shots above. Most of the time the single 3.72GB file copy was consistently fast, but one time, less than halfway through the copy, it went from fast to slow, and remained there for the rest of the copy:

In that case, instead of the usual 14+ seconds, the copy took 2 minutes and 22 seconds! That’s around 27MB/s.

I guess I should mention the other folder copy, the one with the 1,880 files. The time taken was 39.15 seconds to copy from the Windows computer to the Silicon Power PC60, for 43.3MB/s (copying to the LaCie drive was almost identical). All that file opening and closing takes time. Copying it back to the Windows computer from the Silicon Power PC60 took 26.2 seconds (64.6MB/s), which was slower than the 18.76 seconds it took to copy it from the hard drive (90.3MB/s). Here are the write characteristics:

Editors note: Insanity is doing the same thing over and over an expecting a different result.

Because the drive uses a fast, full-duplex interface and the controller is cacheless (as is typical of this type of drive) it expects data to be served faster. In all these examples data was served half-duplex and the peaks and troughs reflect HD signalling.

Gadgetguy’s Take – Great capacity, good price, variable speed

The Silicon Power PC60 packs a lot of capacity into an easily pocketable slim case.

The weird pulsing of write speed – somewhat reminiscent of what you see with a lot of USB memory sticks – was later explained (as you will see from Editors Notes).

The moral of this story is that unless you have USB-C 3.1/2 Gen 2 (like on a Surface Pro 7 or Book 3) all you will get is SATA half-duplex speeds. If that is the case buy a far lower cost external SATA SSD or HDD as you wont use the speed of this device.