The Plextor M3 (256GB) Review
by Kristian Vättö on April 5, 2012 3:05 AM ESTFinal Words
Let's be frank: I'm surprised. When I first got the Plextor M3, I wasn't expecting much from it. A Marvell based SSD from a smaller, somewhat unknown SSD brand is not too promising. If this had been a SandForce based SSD, then we all know what the performance would be like since all OEMs except Intel use the stock firmware. However, Marvell's controllers require a lot more work as the stock firmware that Marvell provides is in need of work. Having your own firmware team is a must if you plan on competing anywhere other than the low-end market. That requires capital, which can be an obstacle for a small firm. With Plextor being a subsidiary of a massive company, they should have the capital they need, and judging by the peformance results, they do.
The Plextor M3 isn't the fastest drive we have tested, but it comes in very close in many tests. It's clearly the fastest Marvell based SSD and it beats its Marvell siblings quite handily in most metrics. SandForce has been and still is extremely fast, but what Plextor has shown is that Marvell's controllers can keep up with SandForce when equipped with great firmware.
I've only really got two complaints. The first one is Plextor's pricing. I think Plextor may be pricing themselves out of competition in the smaller capacities. While the price difference with other brands in 64GB and 128GB capacities is only about $15 on average, that's quite a lot when put into perspective. In percentages, the 64GB M3 is 16% and the 128GB M3 is 9% more expensive than the other drives on average. If you could save 10% on each component in a new system, most people will opt for pricing over brand name.
| NewEgg Price Comparison (4/2/2012) | ||||
| 64GB | 128GB | 256GB | 512GB | |
| Plextor M3 | $110 | $180 | $340 | $660 |
| Crucial m4 | $88 | $155 | $315 | $630 |
| Intel 520 Series | $110 | $180 | $345 | $800 |
| Samsung 830 Series | $105 | $185 | $300 | $780 |
| OCZ Vertex 3 | $90 | $178 | $340 | $770 |
In my opinion, the M3 would be a lot more attractive if Plextor lowered the prices of 64GB and 128GB models by even $10. 64GB and 128GB capacities are often the most popular capacities right now (as spending $300+ on a single SSD is quite rare), so if you want to be competitive, that's the niche you should focus in. Plextor could even increase the pricing on their higher capacity drives while still remaining competitive. Then again, perhaps Plextor is hoping to skip directly to the more lucrative 256GB and 512GB market, as the lower capacity market is already quite cutthroat.
My second complaint is that reviewing the M3 made me lust for something better, and it's called the M3 Pro. The controller is the same Marvell 88SS9174-BLD2 but Plextor has taken the firmware one step further and this has resulted in better performance. I'm not going to go into detail about the M3 Pro here, but it reportedly provides up to 540MB/s read and 450MB/s write speeds along with random read of 75K IOPS and 69K IOPS random write. Hopefully we will be able to get our hands on a review sample soon.
Overall, Plextor M3 is a good performer - and we didn't notice any issues during our testing. It's fast in every aspect, has good gargabe collection, and isn't too power hungry. There is one big unknown though: Reliability. Current generation Marvell based SSDs in general have been fairly reliable, especially when put against SandForce, but firmware plays such a big role with the Marvell controller that you can't really know for sure.
Compatibility and reliability can take months to months to truly understand, so as always proceed with caution. There are great, known good solutions on the market at competitive prices already so there's no need to take a risk on an SSD before its reliability has been proven.
In any case, it's good to see that Marvell's controller still has legs.
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epobirs - Thursday, April 5, 2012 - link
Kind of sad to see a review where Plextor is treated as an unknown. For quite a long time they were the brand against which all others were judged. For one simple reason: ifPlextor said their drive functioned at speed X, it did. If other companies were claiming a new high performance mark and Plextor hadn't produced a matching product yet, it often meant those other companies were lying about their performance.cjcoats - Thursday, April 5, 2012 - link
I'm a scientific user (environmental model), and I have a transaction-pattern I've never seen SSD benchmarks use:My dataset transactions are of the form "read or
write the record for variable V for time T"
(where record-size S may depend upon the variable;
typical values range from 16K to 100 MB).
The datasets have a matching form:
* a header that indexes the variables, their
records, and various other metadata
* a sequence of data records for the time
steps of the variables.
This may be implemented using one of various
standard scientific dataset libraries (netCDF,
HDF, ...)
A transaction basically is of the form:
Seek to the start of the record for variable
V, time T
Read or write S bytes at that location.
NONE of the SSD benchmarks I've seen have this
kind of "seek, then access" pattern. I have the
suspicion that Sandforce based drives will do
miserably with it, but have no hard info.
Any ideas?
bji - Thursday, April 5, 2012 - link
SSDs have no "seek". Your program's concept of "seek" is just setting the blocks that it will be reading to those at the beginning of a file, but from an SSDs perspective, there is little to no difference between the random access patterns used for a particular operation and any other random access patterns. The only significant difference is between random and serial access.My point being, your case sounds like it is covered exactly by the "random write" and "random read" benchmarks. It doesn't matter which part of the file you are "seeking" to, just that your access is non-sequential. All random access is the same (more or less) to an SSD.
This is most of the performance win of SSDs over HDDs - no seek time. SSDs have no head to move and no latency waiting for the desired sectors to arrive under the head.
cjcoats - Friday, April 6, 2012 - link
I guessed you'd understand the obvious: seek() interacts with data-compression.A seek to a 500MB point may depend upon sequentially decompressing the preceding 500 MB of data in order to figure out what the data-compression has done with that 500MB seek-point!
That's how you have to do seeks in conjunction with the software "gzlib", for example.
So how do SandForce drives deal with that scenario ??
Cerb - Saturday, April 7, 2012 - link
Nobody can say exactly the results for your specific uses, but it would probably be best to focus on other aspects of the drives, given performance of the current lot. You might get a 830, while a 520 could be faster at your specific application, but you'd more than likely be dealing with <10% either way. If it was more than that, a good RAID card would be a worthy addition to your hardware.If you must read the file up to point X, then that's a sequential read. If you read an index and then just read what you need, then that's a random read.
Compression of the data *IN*SOFTWARE* is a CPU/RAM issue, not an SSD issue. For that, focus on incompressible data results.
TBH, though, if you must read 500MB into it to edit a single small record, you should consider seekable data formats, instead of wasting all that CPU time.
bji - Saturday, April 7, 2012 - link
They don't use streaming ciphers. They use block ciphers that encrypt each block individually and independently. Once the data makes it to the drive, there is no concept of 'file', it's just 'sectors' or whatever the block concept is at the SATA interface level. As far as the SSD is concerned, no two sectors have any relationship and wear levelling moves them around the drive in seemingly arbitrary (but designed to spread writes out) ways.Basically what happens is that the drive represents the sequence of sectors on the drive using the same linear addressing scheme as is present in hard drives, but maintains a mapping for each sector from the linear address that the operating system uses to identify it, to whatever unrelated actual block and sub-block address on the device that it is physically located at. Via this mapping the SSD controller can write blocks wherever makes the most sense, but present a consistent linear sector addressing scheme to the operating system. The SSD can even move blocks around in the background and during unrelated writes, which it definitely does to reduce write amplification and once again for wear levelling purposes. The operating system always believes that it wrote the sector at address N, and the SSD will always deliver the same data back when address N is read back, but under the covers the actual data can be moved around and positioned arbitrarily by the SSD.
Given the above, and given that blocks are being written all over the flash all the time regardless of how linearly the operating system thinks it has arranged them, there really isn't any concept of contiguously compressed blocks and having to start back at the beginning of some stream of data to uncompress data.
Keep in mind also that the Sanforce drives do de-duplication as well (as far as I know), which means that for many blocks that have the same contents, only one copy needs to actually be stored in the flash and the block mapping can point multiple operating system sector addresses at the same physical flash block and sub-block segment that has the data. Of course it would have to do copy-on-write when the sector is written but that's not hard once you have all of the rest of the controller machinery built.
SSD controllers must be really interesting tech to work on. I can't imagine all of the cool algorithmic tricks that must be going on under the covers, but it's fun to try.
BolleY2K - Thursday, April 5, 2012 - link
Don´t forget about the Yamaha CRW-F1... ;-)Metaluna - Saturday, April 7, 2012 - link
Heh I still have one of those Yamahas, along with some old Kodak Gold CD-R's. I have no real use for them anymore but hate to toss them.Hourglasss - Thursday, April 5, 2012 - link
You made a forgivable mistake with OCZ's Vertex 4. You said the M3 was the fastest non-sandforce drive. The Vertex 4 is made with OCZ's new everest-2 controller that they developed in-house after acquiring indillix (don't know if they spelled that right). So the M3 is fast, but it's second for non sandforce.zipz0p - Thursday, April 5, 2012 - link
I am glad that I'm not the only one who noticed this! :)