The SSD Diaries: Crucial's RealSSD C300by Anand Lal Shimpi on July 13, 2010 12:39 AM EST
Life 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.
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.
|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.
|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 184.108.40.2065 + 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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fgmg2 - Tuesday, July 13, 2010 - linkI know that I could flip back and forth between the various charts to calculate the performance per a watt, but it be great to get a consolidated chart that graphed the drives based upon write (read?) performance per a watt.
Additionally analyzing drives purely based upon their write/read performance and/or purely based upon their power consumption seems a bit meaningless. It should be very easy to make a drive consumes almost no power but writes slower than a 3 1/2" floppy. Especially as you see some drives perform more than twice as fast as others.
Just a suggestion.
P.S. It might not be a bad idea to do the same for your other reviews, such as video cards and CPUs.
7Enigma - Tuesday, July 13, 2010 - linkAgreed. In most reviews (video cards for example) performance per watt is somewhat less important as normally you'll be modeling or gaming and the power draw is going to be pretty stable.
But for a hard drive, especially when many of these will be notebook replacements, it is very important. I have an Intel G2 80GB and love it, and when I look at the power consumption numbers it looks better than the C300. But I'm not naive to the fact that (when TRIM'd) the C300 crushes the G2 in pretty much every benchmark. What that tells me is that in a real-world result the C300 would use more power but get the job done in a shorter time and since we aren't spinning up a traditional platter, the HD behaves very much like a modern Intel CPU and would go idle.
That hurry up and get idle I think would skew those power consumption charts heavily.
What I would design would be a benchmark that has a set instruction set (write 2GB of random, 2 GB of sequential, read 10GB of data), and then measure the TOTAL power of the drive consumed during that time. Then report that total power number and use it for future reviews (a static number to rank similar to a PCMark or Vantage score)
Ernestds - Tuesday, July 13, 2010 - linkI think the best way to calculate efficiency is measuring the total energy used by the drive doing the "Typical Workload" test. Of course, if Anand could do the same with the "Heavy Downloading Workload" it would be great. IMO there is no need for the "Gaming Workload" though, usually who looks for the power graphs is aiming the improvness(does this word exist?) of a notebook's battery life, and frequently who cares about that, do not game on battery.
Just a question to Anand, do you feel difference between two SSDs, say the Nova one and the Crucial?
Keep on the great work!
MrSpadge - Tuesday, July 13, 2010 - linkIt's kind of funny to see someone asking for power efficiency for something which is probably the most power efficient thing in the entire PC, especially if you compare it to HDDs. I understand it's interesting and maybe even important for laptops, though.
I'd rather be interested in more detailed power draw and/or efficiency analysis in case where the power draw really hurts: GPUs and to a lesser extent CPU. For example: how does the power draw of a GF100 improve under load if you watercool it? Sure, not very relevant for most users.. but the difference should be surprisingly large.
shin0bi272 - Tuesday, July 13, 2010 - linkIf you want best overall performance go sandforce. The only real large advantage the crucial drive had was in read performance. sysmark et al were within a few hundred points of one another. So the overall feel of the system will be identical till you either do some heavy read ops or conversely you fill the drive and dont trim it. With the prices being about the same for the 100 vs 128 the better performer is the sandforce drives.
Techdad - Tuesday, July 13, 2010 - linkReally? You'd take the performance tricks and the risk of real data that doesn't fit SandFarce's fancy algorithms over the straight honest performance of the Crucial drive? That's odd.
I've had my Crucial drive since it came out and it's been great. In spite of Anand's corner-case bashing the first version firmware has been rock solid. Debating even if I want to bother with the firmware upgrade, but I'll probably do it.
bji - Tuesday, July 13, 2010 - linkRelying on TRIM and optimizing for the least stressful case is also a "performance trick", so your implication that Sandforce uses such tricks and Micron does not is wrong. Also your childish pun on the Sandforce name shows alot about where you are coming from.
The Sandforce and the Micron drives look to have very similar performance in the vast majority of cases, so shin0bi272 is spot-on. And the increased cost of the Crucial drive would seem to be the deciding factor for me.
But you can't go wrong with either offering it would seem, so pick whichever you like best. As for myself, I would pick Sandforce, only because of my extreme aversion to any chance of degraded drive performance, having been bitten by stuttering of early drives. Not saying that the Crucial drive is anything like a JMicron, but I personally value the resiliency of the Sandforce controller very highly, and would pay some peak performance cost happily for the guarantee of better worst-case performance.
Not everyone will, or should, have the same opinion on this; those less averse to the risks of worst-case performance degredation would be well served by the Crucial drive.
hotlips69 - Tuesday, July 13, 2010 - linkHaving read this review, I'm considering buying one of the 100GB "OCZ Vertex 2" drives used in this article, but I'm not sure exactly which is the correct drive model as there seem to be numerous "Vertex 2" drives on the OCZ website!!
Is it the Pro Series or EX Series or just the standard Vertex 2 series???
hotlips69 - Tuesday, July 13, 2010 - link....also, why is it listed as 120GB in the chart on page 1 of the article?
Anand Lal Shimpi - Tuesday, July 13, 2010 - linkA standard Vertex 2 120GB drive is all you need. The 100GB capacities will probably be phased out by most SandForce partners over time as there's no tangible performance benefit for desktop workloads.
I just used the 100GB data we had in the engine which is why it appears as such in the charts.