The SSD Diaries: Crucial's RealSSD C300
by Anand Lal Shimpi on July 13, 2010 12:39 AM ESTLife just isn’t fair. When I met with Crucial at CES to talk about its first foray into the high performance SSD market I was given very high expectations for reliability and the testing that Crucial would put the drive through. We talked about the failure of other controller vendors to do adequate testing. Even Intel’s own follies. Crucial assured me that validation testing was high on the priority list.
The company already tests hundreds if not thousands of configurations for its memory. Slotting SSDs into the mix wouldn’t be difficult. In contrast, most of the vendors who ship Indilinx and SandForce drives don’t have nearly the validation experience or infrastructure in place to gain it.
Then, just weeks after I got my C300, the drive stopped working. Crucial sent me another drive which didn’t die, but let me discover that the C300 had serious issues when it came to worst case scenario performance. Similar to the original X25-M firmware when given a random enough workload, the RealSSD C300 could be backed into a corner that it would never get out of.
I dropped the C300 from my list of even potential recommendations while Crucial worked on a fix. Meanwhile SandForce’s partners had been shipping drives, with relatively few problems. To make matters worse? The majority of SandForce drives that shipped while Crucial suffered used release candidate firmware. Mass production firmware wasn’t distributed until later. And SandForce did nothing to stop it.
The moral of this story is that entering the storage market is still new territory for everyone. Company size, whether small or large, doesn’t dictate whether you’ll face a failure from a new product. The only guarantee you have is the experience of others who’ve used the drives in configurations similar to your own.
Which brings me to todays topic. I’ve been testing Crucial’s fixed firmware and so far things look good. The situation has improved enough to warrant another look at the C300, including its more affordable 128GB version. And that’s exactly what we’ll do today.
The Drive
I’ve explained how SSDs work in great detail here and here, if you’re a newcomer to all of this I’d suggest looking over those articles.
Like most SSD vendors, Crucial turned to a third party to supply a controller for its SSD - Marvell. Inside Marvell’s controller is a pair of ARM9 CPUs that work in parallel. One core handles SATA requests while the other handles NAND requests.
On the SATA side is a 6Gbps interface, a significant upgrade from the 3Gbps controllers found on all other SSDs we’ve reviewed. If you’ve followed our SSD coverage you’ll know that sequential read speed is one area where SSDs are traditionally limited by 3Gbps SATA. The C300 should fix that. To feed the controller Crucial uses ONFI 2.0 NAND with higher max transfer rates.
While the controller is made by Marvell, the firmware is entirely Crucial’s design. As we’ve seen in the past, as long as the controller’s CPU is fast enough the biggest influence on SSD performance is the architecture of the firmware.
Paired with the controller is an absolutely massive 256MB DRAM. The Marvell controller has a smaller cache than what Intel outfits its X25-M G2 with and rather than demand a more expensive controller with a larger cache, Crucial uses a very large external DRAM to store mapping tables and access history. Micron, Crucial’s parent company, being a DRAM manufacturer probably played a role in making that decision.
The RealSSD C300 is available in three capacity points, two of which I’ll be looking at today: 64GB, 128GB and 256GB. The Crucial controller has 8 channels to its NAND. Both the 128GB and 256GB versions have all 8 channels populated, however the 256GB drive physically has more die per NAND package which allows for greater parallelism and potentially higher performance.
Like the Intel and Indilinx drives, Crucial dedicates around 7% of the drive’s capacity to spare area. This non user-addressable NAND is used as a pool of clean blocks to replace dirty ones during normal use, and to replace any bad blocks.
| Pricing Comparison | |||||||
| Drive | NAND Capacity | User Capacity | Drive Cost | Cost per GB of NAND | Cost per Usable GB | ||
| Corsair Nova V128 | 128GB | 119.2GB | $319 | $2.492 | $2.676 | ||
| Crucial RealSSD C300 128GB | 128GB | 119.2GB | $369 | $2.883 | $3.096 | ||
| Crucial RealSSD C300 256GB | 256GB | 238.4GB | $660 | $2.578 | $2.768 | ||
| Intel X25-M G2 160GB | 160GB | 149.0GB | $405 | $2.531 | $2.718 | ||
| Intel X25-M G2 80GB | 80GB | 74.5GB | $215 | $2.688 | $2.886 | ||
| OCZ Vertex 2 120GB | 128GB | 111.8GB | $329 | $2.570 | $2.943 | ||
| OCZ Vertex 2 240GB | 256GB | 223.6GB | $640 | $2.500 | $2.862 | ||
High end SSDs have dropped in price considerably over the past couple of months. While 100GB SandForce drives were once at or above $400, these days you can get 120GB extended capacity versions for $330. In fact, the price of SandForce drives have dropped so much that there’s pretty much no reason to buy an Indilinx drive at this point. Note that there's no tangible performance difference between the extended capacity SandForce drives and the older versions with more spare area for any of the workloads we'll be talking about today.
Crucial’s C300 is priced competitively with the market, but it does command a price premium over the equivalent capacity SandForce drive. While OCZ will sell you 128GB of NAND on its Vertex 2 for $2.57/GB, Crucial asks for $2.883/GB on its C300.
The Test
| CPU | Intel Core i7 965 running at 3.2GHz (Turbo & EIST Disabled) |
| Motherboard: | Intel DX58SO (Intel X58) |
| Chipset: | Intel X58 + Marvell SATA 6Gbps PCIe |
| Chipset Drivers: | Intel 9.1.1.1015 + Intel IMSM 8.9 |
| Memory: | Qimonda DDR3-1333 4 x 1GB (7-7-7-20) |
| Video Card: | eVGA GeForce GTX 285 |
| Video Drivers: | NVIDIA ForceWare 190.38 64-bit |
| Desktop Resolution: | 1920 x 1200 |
| OS: | Windows 7 x64 |
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Breit - Wednesday, July 14, 2010 - link
yes, a sandforce drive should be slower in general when used with third party encryption as all data seems random to the drive then and the compression algorithms have nothing to compress. i'm not sure if the sf1200 controller can, but the sf1500 controller definitely can encrypt the data on the drive by themself storing it in an aes-128 encrypted format.quote from the sandforce site:
"DuraClass technology automatically stores data in a secure, AES-128 encrypted format. This also prevents would-be thieves from extracting data directly from the flash memory should they ever have access to the drive."
(http://www.sandforce.com/index.php?id=21&paren...
question is how good or usable their implementation is?! :)
sparkuss - Tuesday, July 13, 2010 - link
I asked this question in a previous review and once again you note your "using the Marvell 88SE9128 controller similar to many motherboards".Did you only use the WIN7 MSAHCI and INTEL IMSM 8.9 on both the onboard SATA2 and Rocket 620?
This is of interest to many on the Crucial boards concerning the lack of TRIM support in Marvell drivers for their 9123/9128 controllers.
mattgmann - Tuesday, July 13, 2010 - link
last year the ssd market was pretty cut and clear with what was good and what wasn't. There have been a lot of advances recently, and it's getting hard to keep track of what manufacturers with what controllers work well in what configurations. I'd really love to see an SSD buying guide with all of the current drives, possibly separated into workstation, laptop, and server use sections.thanks
willscary - Tuesday, July 13, 2010 - link
I just sent my first SSD back to Crucial. I called. They RMA'ed me and will send a replacement ASAP. I am impressed. I have 5 year warranties on the M225 series SSDs, and they never even blinked...send it back and they will replace it.This was the only M225 that I have installed that does not have 1916 firmware.
My comment is on the prices. If any of you recall, I was the guy who already had bought, installed and used 5 Crucial M225 128GB SSDs when I decided to try Sandforce in the OWC SSD. After I bought the SSD and ON THE DAY IT SHIPPED, OWC changed their website and said that the controllers were Sandforce 1200 and not the 1500 that I was told when I puurchased. It was still a good deal, but I was upset with the bait and switch, so I refused delivery and had it returned.
I then purchased a Crucial M225 for myself, this one the 256GB flavor.
I want to say that I have had no problems. Peak reads reach about 240MB/s and average reads are about 215MB/sec with large files. Writes are less, about 175-180MB/sec for larger files. With small files like Anand uses, my writes are about 125MB/sec and my small file reads are about 145MB/sec.
Very small files read and write much slower, in the 5-25MB/sec range, but those are files that are very small...in the 4-20KB range.
What amazes me is the speed. While 5MB/sec may sound slow, it is not, at least when you consider that these are 4KB files. These small files write and read nearly instantly.
I paid $525 for the drive. I have seen them as low as $509. This is a great price! Now that I have seen the newest article here by Anand, I really understand that my outdated M225 is still a great deal at $525.
I would like to see this drive, or a comparable one, listed in the lineup with these newer drives. While not as fast, I believe them to be a good value when sale priced. I even saw a Western Digital 128GB SSD a few weeks ago for $219 with free shipping. They were gone very quickly!
Makaveli - Tuesday, July 13, 2010 - link
That was a good read thanks.pesos - Tuesday, July 13, 2010 - link
Hi Anand,Thanks for the followup review - I have been using a 256gb C300 on each of my Poweredge T710 servers for the last few months with great results.
I am curious - does applying the destructive firmware update restore the drive to peak performance, or should it be coupled with some kind of secure erase?
Thanks,
Wes
elimliau - Wednesday, July 14, 2010 - link
Hi,Has anyone made the above work, mine cant?
Regards,
elimliau
sparkuss - Wednesday, July 14, 2010 - link
elimliau,You need to head over to the Crucial SSD forum. I have seen several threads and posts on that specific card/board.
http://forum.crucial.com/t5/Solid-State-Drives-SSD...
sparkuss - Wednesday, July 14, 2010 - link
EDIT: You may have to register to get that link to work, sorryfoo-bar - Friday, July 16, 2010 - link
This is all very interesting, and new SSDs seems to hit the market constantly. But the differences seems to be mostly software related i.e firmware. What are the bottleneck to get full SATA speed? Is it the NAND flash them selves? And if so, what is on the horizon when it comes to this type of memory?