It's called the Intel SSD 320, but the part number should give away just what we're looking at here:

This is the long awaited third generation Intel based SSD. This is the G3. And at this point it's around 6 months late.

Back then it was simply called the Postville Refresh on Intel's roadmaps (Postville was the 34nm Intel X25-M G2). It would use 25nm Intel NAND, feature improved performance and full disk encryption - all behind a 3Gbps SATA interface.

When I spoke with Intel about the drive last year, all indications pointed to it being faster than drives based on SandForce's SF-1200 controller. And it is:

Intel SSD 320 300GB vs. Corsair Force F120
  AT Storage Bench 2011 (Heavy) AT Storage Bench 2011 (Light)
Corsair Force F120 120.1 MB/s 155.9 MB/s
Intel SSD 320 300GB 132.8 MB/s 161.7 MB/s

Without turning to any real time compression/deduplication techniques, Intel has built a drive that's faster than the SF-1200. You also get that famed Intel SSD reliability:

There's just one issue. The SF-1200 was the king of 2010. This year is shaping up to be all about the SF-2200 and the G3 isn't quite as competitive there. Intel realized this as well and thus we got the Intel SSD 510 to address the high performance market. Intel claims the 510 should have the same failure rate as the 34nm X25-M G2 at ~0.6% per year.

The Intel SSD 320 by comparison is aimed at the mainstream market. Remember that's what the M in X25-M always stood for to begin with. As a result we get lower pricing:

Intel SSD Comparison
  X25-M G2 160GB Intel SSD 320 40GB Intel SSD 320 80GB Intel SSD 320 120GB Intel SSD 320 160GB Intel SSD 320 300GB Intel SSD 320 600GB SSD 510 120GB SSD 510 250GB
User Capacity 149GB 37GB 74GB 111GB 149GB 279GB 558GB 111GB 232GB
Random Read Performance Up to 35K IOPS Up to 30K IOPS Up to 38K IOPS Up to 38K IOPS Up to 39K IOPS Up to 39.5K IOPS Up to 39.5K IOPS Up to 20K IOPS Up to 20K IOPS
Random Write Performance Up to 8.6K IOPS Up to 3.7K IOPS Up to 10K IOPS Up to 14K IOPS Up to 21K IOPS Up to 23K IOPS Up to 23K IOPS Up to 8K IOPS Up to 8K IOPS
Sequential Read Performance Up to 250MB/s Up to 200MB/s Up to 270MB/s Up to 400MB/s (6Gbps) Up to 500MB/s (6Gbps)
Sequential Write Performance Up to 100MB/s Up to 45MB/s Up to 90MB/s Up to 130MB/s Up to 165MB/s Up to 205MB/s Up to 220MB/s Up to 210MB/s (6Gbps) Up to 315MB/s (6Gbps)
Price $404 $89 $159 $209 $289 $529 $1069 $284 $584

It's still early in the 25nm ramp, but the 25nm Intel SSD 320 is cheaper than the 34nm Intel SSD 510. The only issue is that OCZ is very competitive with its pricing as well and compared to the Vertex 2, Intel's SSD 320 isn't really any cheaper. Intel likes to maintain its 65% profit margins so even though it makes the NAND and the controller in the 320, we're unlikely to see these drives drop below competitive pricing.

Intel expects the 25nm SSD 320 to be even more reliable than the 510 or X25-M.

The Same Controller

The Intel SSD 320, like the 310 and X25-M before it, uses an Intel branded controller. Opening up the 320 reveals a near identical controller to what we saw in the 34nm X25-M G2 housing:

You'll notice the part number is identical to 2009's X25-M G2 controller. In fact, it's the same controller. Apparently the G2 controller had a number of features on-die, but not implemented in firmware. Things like full disk encryption and NAND redundancy never made it out in G2 but are here in the 320 all thanks to new firmware. And no, G2 owners aren't getting it.

Intel's X25-M G1 Controller

Intel's X25-M G2 Controller

Intel's SSD 320 Controller

Since the controller hasn't changed, the basic architecture of the SSD hasn't changed either. Intel still doesn't store any user data in its external DRAM cache and there's still a 256KB on-die SRAM.


Next to the Intel controller is a 64MB 166MHz SDRAM device, now made by Hynix. You'll notice that the DRAM chip is a lot smaller than what we've seen in previous X25-M generations, despite growing in capacity. Intel actually turned to mobile SDRAM for use in the SSD 320 to help save on power. While the X25-M G1 and G2 both used a conventional 3.3V SDRAM device, Intel moved to a 1.8V mobile SDRAM chip with the 320.

Intel X25-M G1: 16MB 166MHz SDRAM

Intel X25-M G2: 32MB 133MHz SDRAM

Intel always prided itself on not storing any user data in its DRAM cache. The external DRAM is only used to cache mapping tables and serve as the controller's scratchpad. In the event of a sudden loss of power, Intel only has to commit whatever data it has in its SRAM to NAND. To minimize the amount of data loss in the event of a sudden power failure, Intel outfitted the SSD 320 with an array of six 470µF capacitors in parallel.

We've seen large capacitors on SSDs before, primarily the enterprise SandForce drives that boast a 0.09F supercap. Intel claims that for its design a single large capacitor isn't necessary given the minimal amount of data that's cached. It further claims that an array of multiple capacitors in parallel allows for much better reliability - if one capacitor fails the array is still useful (vs. a single point of failure in the case of the supercap).

Spare Area, 3Gbps Only, AES-128


View All Comments

  • semo - Monday, March 28, 2011 - link

    Anand, it has been a long time now. People are still confused about what is happening with the OCZ V2 drives. OCZ are still not issuing a recall of drives that are smaller and slower than what the packaging claims.

    OCZ will only react when the customer finds out through their own research what has happened and then confronts OCZ.

    For those wanting to know more, see my thread below or research the OCZ Vertex 2 25nm transition fiasco.

    The issue will not be resolved until OCZ recalls all affected products.
  • GeorgeH - Monday, March 28, 2011 - link

    It looks like the crucial parts are physically identical to G2 drives. Intel may not offer updated firmware for G2 drives, but it looks like it might not be impossibly difficult to modify G3 firmware to work on G2 drives.

    Did Intel give any indication if the G2 controllers were physically different from the G3s? In other words did Intel take the laser scalpel to the G2 controllers or is it just a software restriction?
  • Chloiber - Monday, March 28, 2011 - link

    Anand explained why the write performance is higher (4kB -> 8kB). Reply
  • GeorgeH - Monday, March 28, 2011 - link

    Sure, but full disk encryption might be nice. Reply
  • Anand Lal Shimpi - Monday, March 28, 2011 - link

    The G2 controller had the same features as the 320's controller. It's unclear whether they were tested/functional in the G2 era but they were there. The 320's controller is apparently the same physical die, just with these new features enabled/tested/validated.

    G1 owners didn't get TRIM, and I wouldn't expect G2 owners to get AES-128 via firmware. Sorry :(
  • bbbcase - Monday, March 28, 2011 - link

    The Intel G1/G2 drives would eventually throttle write performance if you consistently wrote over 20GB/day on them to ensure warranty lifetime. This really limited their usefulness in certain server applications.
    Does the G3 have a similar throttling mechanism?
  • Chloiber - Monday, March 28, 2011 - link

    ?? They didn't. The block fragmentation will, in spite of TRIM increase (that's the case with pretty much every SSD). Write 0s sequentially on the empty space every 2 months and the performance will always be as it was on the first day.
    You can also do this by doing a Full Diagnostics Scan using the Intel SSD Toolbox (writes sequentially on the empty space).
  • toyotabedzrock - Monday, March 28, 2011 - link

    I'm curious if a 8KB random R/W test would show a bump in speed beyond what other drives would see.

    Intel really needs to get serious about allocating people to the SSD and Chipset teams. They always make a quick leap with a great new chip then it languishes for years with minor updates.

    Pentium 4 flashbacks!
  • cdbob - Monday, March 28, 2011 - link

    I heard rumors that pricing was going to be on the steep side. It's too bad this turned out to be true, Intel better lower the price of their drives quick or they're going to start eating some serious dust when the next crop of Crucial Drives come out. Reply
  • Beenthere - Monday, March 28, 2011 - link

    That's why I won't buy any SSD for at least five more years. Poor reliability and data loss don't work for me. Reply

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