The Crucial/Micron M500 Review (960GB, 480GB, 240GB, 120GB)
by Anand Lal Shimpi on April 9, 2013 9:59 AM ESTAnandTech Storage Bench 2011 - Light Workload
Our new light workload actually has more write operations than read operations. The split is as follows: 372,630 reads and 459,709 writes. The relatively close read/write ratio does better mimic a typical light workload (although even lighter workloads would be far more read centric).
The I/O breakdown is similar to the heavy workload at small IOs, however you'll notice that there are far fewer large IO transfers:
AnandTech Storage Bench 2011 - Light Workload IO Breakdown | ||||
IO Size | % of Total | |||
4KB | 27% | |||
16KB | 8% | |||
32KB | 6% | |||
64KB | 5% |
The story in the light workload looks a bit better. While the M500 still pulls up the rear, the margin of victory for the 840 and other drives is much smaller.
111 Comments
View All Comments
BHSPitMonkey - Tuesday, April 9, 2013 - link
Correction: "securily" should read "securely" in the section about encryption.iaco - Tuesday, April 9, 2013 - link
Only 72 TB of writes? That must be a mistake. That's even worse than Samsung's TLC NAND with 1000 write cycles. At 500 GB, 1000 cycles is equal to 500 TB. 3000 cycles for MLC NAND is 1500 TB. Anand, please tell me the spec is wrong, otherwise this drive is not worth the price.Anand Lal Shimpi - Tuesday, April 9, 2013 - link
That's directly from the M500 datasheet. Note that Intel rates the 335 at 20GB of writes per day for 3 years or 21.9TB but explicitly calls that out as a minimum endurance. I suspect that's what this 72TB rating is as well. Samsung doesn't publish similar numbers for the 840 and everyone comes up with their endurance numbers in different ways so they wouldn't likely be comparable either.The NAND is no less reliable than previous 20nm versions, so I have no reason to believe we won't see significantly longer lifespan out of the M500 than just 72TB of writes.
Take care,
Anand
microlithx - Tuesday, April 9, 2013 - link
If you look at Micron's data sheets, particularly at the enterprise SATA SSDs, you'll see they report 7 PB. They won't guarantee it but they'll probably reach that if you overprovision accordingly.NotablePerson - Tuesday, April 9, 2013 - link
What I'm confused about is how the 72TB endurance rating is the same across the board for all four of the SSDs. Shouldn't there be at least SOME variance in their ratings on account of the additional NAND?Kristian Vättö - Tuesday, April 9, 2013 - link
I don't have the datasheet with me (I'm travelling this week) but that 72TB was not sequential writes. IIRC it was 90% random and 10% sequential (and a couple of different IO sizes too), hence the endurance rating. Anand should be able to confirm the exact methodology but 72TB sounds normal in my ears, some have ~30TB (but 100% 4KB random writes).Solid State Brain - Wednesday, April 10, 2013 - link
I believe this is their way of telling buyers that they do not officially support or endorse enterprise usage (ie more than 40 GiB/day) on these drives, although their NAND flash memory is specced for way more than just 72 TiB of writes especially on higher capacity models.I would expect the 960 GB (1 TiB) drive to unofficially endure for at least 1.5 PiB of writes (at 2x write amplification).
Solid State Brain - Wednesday, April 10, 2013 - link
I meant to say that the 960 GB model (894.07 GiB) has 1 TiB of flash memory installed on its PCB. The "missing" capacity is for overprovisioning purposes.comomolo - Friday, May 3, 2013 - link
I can't believe they sell a 1TB drive that will day after fully writing it just 72 times.theduckofdeath - Tuesday, April 9, 2013 - link
This was a bit disappointing, I think. Hopefully a FW update or two will improve the numbers a bit, otherwise it just feels like a step backwards if you're not going for the 1TB model.