After having recently reviewed the Silicon Power Stream S10 750GB portable USB 3.0 hard drive we were keen to check out the newer Stream S20 model. However around the same time Silicon Power also released the Diamond D10 which featured similar specifications, and therefore we thought it prudent to review both products.

Of course you might be thinking these are just more portable devices that feature a 2.5” laptop hard drive and the ability to utilize the USB 3.0 interface. After all, this is essentially what the Stream S10 was so how different can the Stream S20 and Diamond D10 be? Honestly we were thinking the same thing and it seems curiosity got the better of us.

On the surface all three products look very different, though in terms of pricing they are very similar. Whereas the 750GB version of the Stream S10 is still fetching $82 US, the Diamond D10 costs $85 US, and the Stream S20 slightly more at $87 US. It is a very real possibility that all three products make use of the same hardware, as in they use the same hard drive and USB 3.0 bridge chip.

Thankfully this is not the case, at least not entirely, as Silicon Power has shopped around when selecting the 2.5” hard drives. Whereas the Stream S10 employed the Toshiba MK7559GSXP hard drive, the Diamond D10 is fitted with a Western Digital Scorpio Blue hard drive. How much difference users can expect to see in terms of performance is yet to be seen, but this is certainly something we will be looking into.

However, before we check out how each one of these Silicon Power 2.5” USB 3.0 portable drives performs, let’s take a moment to take a closer look at the Stream S20 and Diamond D10.

The 750GB model that we have costs just $85 US, while the smaller 500GB version can be had for $70 US. The flagship 1TB model, which is currently out of stock everywhere we looked, costs $98 US.

Given that the cheaper 750GB drives we have come across all cost around $85-$90 US, the Silicon Power Diamond D10 750GB appears to be remarkably good value. That said, it will be interesting to see how the drive performs, as Silicon Power neglected to list any kind of performance numbers on its website.

The Diamond D10 comes in either pink or blue (no prizes for guessing which color we were sent), and features a 100% plastic housing. While the plastic housing is quite durable, it is not designed to survive a serious fall, so for those that play rough this might not be the safest way to transport your data. The case includes a small built-in blue LED status light that indicates power on and activity status.

Pulling apart the Diamond D10 gave us a better understanding of what makes this product work. Inside is a Western Digital Scorpio Blue 750GB (WD7500BPVT) laptop hard drive. This particular drive retails for $80 US, features a 5400 RPM spindle speed and an 8MB cache.

Connected to the Western Digital 2.5” drive is a small PCB which features an ASMedia ASM1051 single chip USB 3.0 controller. For those not familiar with ASMedia they are a subsidiary of Asus and they have been producing USB 3.0 controllers since early 2010. The ASM1051 can deliver performance that is several times greater than the Scorpio Blue drive, so there will be no bottleneck here.

The Diamond D10 is very light, weighing in at just 155 grams (205g for the 1TB model), while measuring just 124.8cm long x 75.8cm wide x 13.6mm thick. The 1TB model shares the same length and width dimensions while it is slightly thicker at 16.6mm.

Keeping the Diamond D10 safe is a dedicated protection pouch which helps protect the drive when tossed into a bag for example. Finally, Silicon Power has included a comprehensive three-year warranty to back the Diamond D10 portable USB 3.0 drive.

The 750GB model that we have costs just $87 US, while the smaller 500GB version can be had for $72 US. The flagship 1TB model, which is currently out of stock everywhere we looked, costs $102 US.

As we found when looking at the Diamond D10, it costs around $85-$90 US for a 750GB 2.5” hard drive, making the Stream S20 750GB at $87 remarkably good value.

The Stream S20 comes in just one color which is dark purple, and features a 100% plastic housing. While the plastic housing is quite durable, it is not designed to survive a serious fall, so for those that play rough this might not be the safest way to transport your data. The case includes a small built-in blue LED status light that indicates power on and activity status.

Pulling apart the Stream S20 gave us a better understanding of what makes this product work. Inside is a Samsung Spinpoint M8 (HN-M750MBB) laptop hard drive. This particular drive retails for $65 US, features a 5400 RPM spindle speed and an 8MB cache.

Connected to the Samsung 2.5” drive is a small PCB which features an ASMedia ASM1051 single chip USB 3.0 controller, the same design used by the Diamond D10. In fact thus far it appears that all current Silicon Power USB 3.0 portable hard drives are based on the same design.

The Stream S20 is very light, weighing in at just 160 grams (210g for the 1TB model), while measuring 142.4cm long x 80.1cm wide x 21mm thick. This makes the Stream S20 considerably thicker than the Diamond D10.

Keeping the Stream S20 safe is a dedicated protection pouch which helps protect the drive when tossed into a bag for example. Finally, Silicon Power has included a comprehensive three-year warranty to back the Stream S20 portable USB 3.0 drive.

Hardware - Intel Core i7-2600K (LGA1155) - x2 4GB DDR3-1600 G.Skill (CAS 8-8-8-20) - Samsung Spinpoint F1 1TB 7200-RPM (Serial ATA 3Gb/s) - Asus GeForce GTX 580 (1536MB) - Asus P8P67 Deluxe (Intel P67) - OCZ ZX Series (1250w) Software - Microsoft Windows 7 Ultimate SP1 (64-bit) - Nvidia Forceware 275.33

Like all mechanical hard drives the Stream S20 and Diamond D10 perform poorly when measuring random 512 byte performance.

The random read 1MB performance is much more impressive and here the Stream S20 manages a throughput of 32.9MB/s while the Diamond D10 was slightly slower with 31MB/s. Interestingly both were slower than the Stream S10 which sustained 39.6MB/s.

The random read random file size performance of the Stream S20 and Diamond D10 was again slower than that of the Stream S10. The Stream S20 was a fraction faster than the Diamond D10, though there was very little in it.

When measuring the sequential read/write performance we found that the Stream S20 was the leader here, beating the Diamond D10 by a convincing margin, while the Stream S10 can be found virtually right in the middle. Impressively when compared to expensive USB 3.0 flash memory devices such as the Kingston DataTraveler Ultimate 3.0 and Patriot Supersoinc, the Silicon Power USB 3.0 hard drives are very competitive and in some cases faster.

When measuring random 512K read/write performance the mechanical hard drives begin to show signs of weakness. The Stream S20 managed just 38.4MB/s when measuring read performance and just 16.7MB/s when writing. The Diamond D10 was faster when looking at write performance and slightly slower in the read test. The Stream S10 was again a more consistent performer delivering comparable read performance coupled with much stronger write performance.

Finally the random 4K-QD32 test, and again this is where mechanical drives fall over. While all products that are based on a traditional hard drive were limited to well under 1MB/s, those using NAND flash memory were several times faster.

When copying a file from the Stream S20, or as we call it downloading, a throughput of 104.3MB/s was achieved. This made the Stream S20 slightly faster than the Stream S10 and more than 10MB/s faster than the Diamond D10. Still, while all three Silicon Power portable USB 3.0 drives displayed strong performance, we were most impressed with how the Stream S20 kept pace with the Kingston DataTraveler Ultimate 3.0.

The game copy test provided similar performance trends as the Stream S20 lead the charge for the mechanical drives. In this test it did fall behind the Kingston DataTraveler Ultimate 3.0, which appears better equipped to handle multiple smaller files, likely due to its 0ms access time.

Interestingly in our program copy test the Stream S10 overtook the Stream S20 by quite a large margin. In fact the Diamond D10 also overtook the Stream S20, which seemed to have trouble with this test. With a throughput of 51.6MB/s the Diamond D10 was still much faster than even the fastest USB 2.0 device.

When copying data to the Stream S20 it sustained a transfer rate of 86.5MB/s, while the Diamond D10 was just a fraction slower. In fact the Stream S20 delivered the same performance as the Stream S10 and with all three Silicon Power USB 3.0 drives exceeding 80MB/s they were faster than the Patriot Supersonic and Kingston DataTraveler Ultimate 3.0.

The game upload test mixes things up quite a lot and the Stream S20 performed exceptionally well in this test. Here it was faster than even the Patriot Supersonic Magnum with a throughput of 63.4MB/s, meanwhile it destroyed the Diamond D10 which managed just 49.1MB/s.

The program upload test normalized the results and once again all three Silicon Power USB 3.0 portable drives delivered virtually the same performance. The Stream S20 achieved 33.2MB/s, while the Diamond D10 was a fraction slower with 30.7MB/s.

The on-disk copy performance of the Stream S20 was much stronger than the Diamond D10, as it sustained 30.1MB/s opposed to just 32.2MB/s. The Stream S10 was also slower as it managed just 26.1MB/s.

Strangely, while the Stream S20 dominated the large single file test it struggled with the game copy test, delivering just 23.1MB/s opposed to the 30.8MB/s of the Diamond D10. Meanwhile the Stream S10 was faster than both drives, delivering 34.2MB/s.

The last copy test using our program sample data saw the Diamond D10 match the Stream S10 with 24.6MB/s, while the Stream S20 managed just 20.3MB/s.

That said, you really cannot go wrong with any of these drives, as they all offer solid performance across the board. The Stream S10 was surprisingly fast in a number of tests and while we were not impressed with the Toshiba MK7559GSXP hard drive originally, it appears to hold its own very well.

The Western Digital Scorpio Blue hard drive utilized by the Diamond D10 is a solid product and at $95 US for the 750GB version, you have to appreciate that Silicon Power are selling this model for just $85 US, clearly they are getting a bulk discount from WD.

However our preference is again the Samsung Spinpoint M8 which is of course used by the Stream S20. Although the Stream S20 did display superior performance in a number of tests and will cost a few dollars more than the Stream S10 and Diamond D10, the Samsung Spinpoint M8 750GB hard drive only costs $65 US. Therefore it seems strange that Silicon Power are charging a slight price premium for this product.

Clearly they know the Samsung hard drive is the best performer and can therefore charge the most for the Stream S20. However in reality, while users cannot build a cheaper version of the Stream S10 or Diamond D10, they can in fact build a cheaper Stream S20. This can be done by purchasing the Samsung Spinpoint M8 750GB hard drive coupled with a USB 3.0 enclosure which we estimate can be done for just $80.

Even so, a saving of just $7 at best is probably not worth ditching the impressive looking Stream S20 shell for a cheap external enclosure. Silicon Power really has done an excellent job pricing these portable USB 3.0 hard drives as there are no cheaper 750GB options that we know of. Western Digital’s own My Passport Essential SE costs $90, while the Hitachi Touro Mobile Pro 750GB costs $95.

Overall we are pleased with the performance and price of the Silicon Power Stream S20 and Diamond D10 750GB drives, and we believe them to be pretty cool looking products. Even if there is nothing sedate about the bright pink and purple color schemes, we still feel they will appeal to most.