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I have an old EEE PC with the 4 Gig internal drive. Everything I've read keeps saying it's an SSD drive; running lshw tells me that it's an ATA disk, Silicon Motion SM. The thing seems to be rather slow, though. I know it has a 900 Mhz Celeron processor and only 512 meg of RAM, but it seems like drive access is slow even for those specs. Does anyone know if it really has an SSD drive? I thought that compared to regular hard disks SSD's were blazing fast, and this feels like and acts like it's pulling from something more akin to an internal USB memory stick.

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The drive is almost certainly an SSD. There are a few reasons why the performance may seem poor:

  • SSDs tend to be faster the larger the drive (and the more free space that is available), so a 4GB drive very unlikely to match the speeds of modern SSDs which are usually >= 64GB.
  • The performance of SSDs tends to diminish over time (as David points out), unless the drive and OS support the TRIM command.
  • This SSD may have a relatively basic (and hence cheap) controller, i.e., the controller has limited RAM and processing power for performance optimisation.
  • Some of the early SSDs/controllers suffered some issues which caused "stuttering".
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Re: drop in performance over time...what kind of performance loss is seen? For example, on Macs you can get MacBook Air's that are only SSD drives or MacBook Pros with 128 and 256 meg SSD's; will their performance degrade to a point where they're worse than the stock hard drives you would normally get in them? (I don't think they support the TRIM command set, unless Apple is planning some kind of workaround down the road with a firmware update and OS update...) –  Bart Silverstrim Mar 13 '10 at 22:21
    
@Bart AnandTech have a good comparison of the new vs. used performance of some (slightly old) SSDs: anandtech.com/storage/showdoc.aspx?i=3531&p=13. In the worst case scenario, some of the SSDs do perform worse than HDDs, in terms of random write latency. –  sblair Mar 13 '10 at 22:46
    
Good article, thanks. Looks like from what they're saying...if I were to generalize...SSD drives, even "used" and degraded, still outperform traditional hard disks, just aren't as fast as when you first "use" them. –  Bart Silverstrim Mar 14 '10 at 0:15
    
Also, being ATA and not SATA has its own performance bottleneck in this situation. Very possible that the disk itself is not the slow part of the disk access equation, the ATA bus is slow in general. –  spowers Mar 14 '10 at 1:25
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The SSDs in netbooks are not the expensive blazing fast variety, and their performance can degrade over time just like their faster, more expensive, contemporaries. I would not be surprised to find the SSD in your machine is using the same RAM chips and controller as found in some USB memory sticks. USB memory sticks are SSDs, just made with different priorities (cheap + portable + just fast enough).

If I test the internal SSD of my Acer Aspire One, by write a large chunk of data then running sync to ensure all is written and timing the whole operation, I see a bulk write rate of a little less than 4Mbyte/second which is very slow. The bulk read speeds were more acceptable (and a lot better than most USB sticks) though at ~32MByte/sec. I've not tested more random access patterns - I expect it will fair better in such tests as this is where even slow SSDs tend to do well against mechanical drives.

I found some microSD cards I had wrote faster in the mini USB adaptors I have them in (like these). I've actually got Ubuntu installed on a pair of them using RAID0. The overall bulk read speed is about the same as the built-in SSD (~32Mbyte/sec) but the bulk write is much better (varying between 12 and 16Mbyte/sec) though I expect this to drop over time. Again I've not got around to doing performance tests for more usual and/or more random I/O patterns (i.e. many small reads and writes rather than bulk operations), but the speed difference in the system's general responsiveness is definitely significant in general use. The micro card readers are small enough to leave plugged in constantly (though it does mean I lose two USB ports, but more of the time this is fine as it leaves on free for bluetooth / a mouse / another drive and for other times I carry a small USB hub).

Edit:

I don't know about the EEE models like your's but the Acer's SSD is a standard 1.3" PATA device with ZIF connector, so can be replaced if you dare pull it apart (I keep considering treating myself to something like this, but money is short right now and my 2x USB mSD arrangement is proving more the sufficient for the time being). So you might be able to replace your slow device with something more capable - the mod community seems quite active around netbooks so if it is possible a quick search should find a few good tutorials.

As well as the drive space differential (4/8/16 Mb compared to ~160), the slow speed of cheap SSDs and the expense of faster ones is why SSD based netbooks are becoming rarer - the buying public prefer the storage space and write speed of a spinning disk over the random access speed and no-moving-parts-y-ness of an SSD at the same price, particularly when running Windows (which, especially with a small amount of RAM, seem much worse affected by the slow write speed than Linux in my limited experience of Windows on these things and needs more space to be useful).

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