|IOCELL NetDISK 351UNE Network Storage Device|
|Reviews - Featured Reviews: Network|
|Written by Bruce Normann|
|Monday, 28 November 2011|
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Insider Details: IOCELL NetDISK 351UNE
The NetDISK 351UNE comes apart easily, by removing two screws on the bottom, and then separating the two halves of the unit. They're not quite equal halves, as the side shown on the left below is more of a cover and the one on the right is more of an enclosure. Despite the molded plastic construction, it all fits together cleanly, with no gaps or exposed flashing. The case has a lot of open area around the edges, and I'm surprised the designers didn't go for something a bit smaller in overall size.
The construction inside is very straightforward and robust. It's almost as if the 351UNE was designed to be a portable drive, instead of a transportable device.
The metal drive tray is quite solid, and constructed of carbon steel. There were no sharp edges or other manufacturing defects that you sometimes see with products on the lower end of the price range. It's always nice when you can finish an entire review without using any adhesive bandages.
Taking a closer look at the system board, it doesn't look like much, but each function is managed by a dedicated Application Specific IC (ASIC). I'll detail them in the very next section, but here's how they line up. The key IC on the board is the NDAS disk controller, sourced from the originator of NDAS technology, Ximeta. It's also the largest chip, second from the left, sandwiched between the Ethernet transceiver on the left, and the SATA bridge that supports the eSATA port. The fourth large chip from the left is the USB to SATA bridge device that supports the USB 2.0 port, the interface of last resort. Most of the other visible components are power management ICs or discrete passives. There's actually a lot of Silicon here on this small PC board, which is an indicator of the enhanced functionality this unit offers over a typical external storage box. OTOH, it's less than you would typically see in a NAS server, which also makes sense, given the lightweight nature of the LPX protocol that Ximeta pioneered. Significantly absent is any form of CPU, which IOCELL says is a good thing. Testing is where Benchmark Reviews will validate that claim.
Now, let's look at each of the four major ICs in detail. The first one is a USB/SAT to SATA bridge, sourced from 'initio'. It's not a name I'm familiar with, but they've been around Silicon Valley since 1994, so they must be doing something right. The INIC-1611 is capable of transferring data at 60MB/s on the USB side, and 150MB/s on the SATA side. This is equivalent to SATA I performance specifications, although the chip will support both SATA II and eSATA interfaces. The largest and most interesting chip on the board is the Ximeta NDAS3012, which houses all the proprietary NDAS functionality that makes the NetDISK 351UNE fairly unique in the marketplace. All of the distinctive features that we've discussed in the first several sections of this review are due to the code that runs on this IC. It's a tight, fast, direct link between Ethernet and SATA that you just won't find any place else. It doesn't do everything; there are a couple of kitchen-sink items that still need taking care of, which is why there are four major chips on the board, instead of two.
JMicron supplies their JM20330 SATA bridge IC that supports eSATA. Just like the USB connection, this chip only supports a data transfer rate of 150MB/s, which is SATA I class performance. While this was not an issue for dog-slow USB 2.0, eSATA is capable of so much more throughput. I suspect it's not going to a huge success to use this NetDISK 351UNE as a high-performance eSATA drive, with a killer HDD loaded inside. In fact, IOCELL recommends "Green" HDDs anyways, due to the lower current draw for their low-speed spindle motors. ("High performance hard disks, especially ones which have high starting current consumption of over 2.5 Amp, are not recommended.") The last chip to look at is a Gigabit Ethernet Transceiver sourced from LSI. It's a bit ironic that LSI, which is such an iconic brand in storage controller technology, is supplying just an Ethernet controller here. The reality is that LSI's storage products are aimed at a completely different market (enterprise solutions), and if they also happen to make a decent GbE transceiver for a good price, why not use it?
To measure isolated NAS power consumption, Benchmark Reviews uses the Kill-A-Watt EZ (model P4460) power meter made by P3 International. Obviously, power consumption is going to depend heavily on the type of drive that's installed. In idle standby mode the IOCELL NetDISK 351 UNE consumed just 6 watts of electricity. During heavy file transfer operations, it drew between 16 and 17 watts. Read and write consumption was similar, I never saw a consistent difference between the two.
We've seen the ins and outs of the hardware; now let's take a detailed look through the list of features and the included software that you get with the NetDISK NDAS product line. It's a much shorter list than you're used to seeing in our NAS reviews, but there are a few unexpected tricks that these units can do. You don't want to be fooled into thinking it's just a box and a drive.