Most folks will never even come close to exceeding the write endurance limits of today's desktop-oriented SSDs. Write exhaustion requires continuous writing to a drive for weeks and months on end before you completely exhaust the usable life of each NAND cell.
In the enterprise world, however, this is a much more likely scenario. Knowing the write endurance of an SSD can help IT professionals select drives that are best suited to their tasks.
When Intel released its first enterprise drive, X25-E, the company did not publicly state write endurance specifications. With its two subsequent offerings, though, Intel was very specific about what results were achievable and how to achieve them. The 400/800 GB versions of the Intel SSD 910 have a stated write endurance of 7 and 14 PB, respectively. According to Intel, write endurance is measured while running 100% random 4 KB and 8 KB writes spanning 100% of the SSD using Iometer. This is, by far, the worst-case scenario. In a mixed workload, you'd see more favorable results, as we will see.
Before we dig into the results, if you are unfamiliar with the different types of NAND or the concept of write exhaustion in general, take a look at our reviews of the Toshiba MK4001GRZB and Intel SSD 710.
To test write endurance, we wrote large block, sequential data to the drive, while continuously monitoring the MWI (Media Wearout Indicator). The MWI reports, from 0-100, the percentage of life that has been used on the drive. We started with a clean drive and wrote to it until the MWI reached 1%. It should be noted that each of the four NAND modules has its own MWI. The data below is based on when the first module reported a change to the MWI. The other three modules all changed within ~150 GB of the first. This difference only accounted for ~0.15% of the total number of writes.
By writing sequential data, we are showing the maximum usable life of the NAND itself, removing outside factors like wear-leveling and garbage collection. In this configuration, the write amplification should be very close to 1.0.
| Endurance Rating Sequential Workload, QD=1, 8 MB, Random | Intel SSD 910 | Intel SSD 710 | Intel X25-E | Toshiba MK4001GRZB |
|---|---|---|---|---|
| NAND Type | Intel 25 nm eMLC (HET) | Intel 25 nm eMLC (HET) | Intel 50 nm SLC | Toshiba 32 nm SLC |
| RAW NAND Capacity | 896 GB | 320 GB | 77GB | 512 GB |
| IDEMA Capacity (User Accessible) | 800 GB | 200 GB | 64 GB | 400 GB |
| Over-provisioning | 12% | 60% | 20% | 28% |
| P/E Cycles Observed (IDEMA) | 46 339 | 36 600 | 237 968 | 225 064 |
| P/E Cycles Observed (Raw) | 41 374 | 22 875 | 198 307 | 175 831 |
| Host Writes per 1% of MWI | 370.71 TB | 73.20 TB | 152.3 TB | 900.2 TB |
| $/PB-Written | $106.60 | $181.72 | $60.51 | $79.63 |
In terms of P/E cycles observed, the Intel SSD 910 outperforms Intel's SSD 710 by 80%, even though they use the same NAND. But, as with all MLC-based flash, it can’t really hold a candle to good old-fashioned SLC.
So why, in an enterprise application, where write endurance is so important, would you consider anything other than SLC? Simply, cost. HET MLC (or eMLC) offers a solid middle-ground to those that need enterprise-level write endurance, but can’t justify the price of SLC-based drives. Intel's SSD 910 makes that value proposition even more intriguing compared to its SSD 710.
When you look at just write endurance and cost ($/PB-written), ignoring all other factors, the SLC-based X25-E is still the clear winner. But the comparison to the SSD 910 is much better-looking than the SSD 710. This is important for customers who want to use these drives purely as write-caching devices, where speed and size can be secondary features.
- SSD 910 Gets A True Enterprise-Class Workout
- When One SSD Is Actually Four
- Default Versus Maximum Performance Mode
- Test Setup And Benchmarks
- Testing Methodology
- Write Endurance
- 4 KB Random Performance
- Enterprise Workload Performance
- Sequential Performance
- Enterprise Video Streaming Performance
- Power Consumption
- Temperature
- Is Intel's SSD 910 Right For Your Enterprise Application?
Review sites never cover real world use - that is to live with it day in day out (reliability), its not all about raw speed and performance.
As best I understand it as it was descibed by the company that analyzed these failed drives, a block of NAND flash either went bad or became inaccessible by the controller rendering the drives useless and unable to be accessed by normal means of hooking it up to a SATA or USB port. Two drives, different NAND (50 nm for the G1 and 34 nm for the G2), same failure mode.
Once again, this is not definitive, just my observations but to me, I think review sites need to be a little more cautious about how they qualify intel's reputation for quality and reliability because from my perspective, intel has neither and I have since began using crucial SSD's. Hopefully, I will see much longer life from these new drives.
Intel, you should test these drive in that real world application. EMC, VM-ware and several data bases carve out some LUN's and Push the envelope. In this situation, should the device prove worthy, the 4000 price tag will come down very fast, and the data center will put it trust in product, So for those reading this for your personal home workstation and gaming ridge, you need not apply in this arena.
Intel is just about 18-months 2 years of owning the data center, Even EMC is powered by intel.
That's because this was not designed for consumers. It's not like they're marking the price up 1000% for shits and giggles. Enterprise hardware costs more to make because it must be much faster and much more reliable.
This drive, and every other piece of enterprise hardware out there, was never meant to be used by consumers.
Check out the Sequential Performance page, lists both compressible and incompressible. For all the other tests, random (incompressible) data was used.
I agree that we shouldn't use blanket statements, especially on quality, without going through the proper process. Intel has had many issues with their consumer lines, X25-M, 320, etc. I have personally worked with large distributions of their enterprise drives and they are rock solid. Other studies, including articles on this site, have shown the same in real-world scenarios.
Best of the best NAND ? firmware? overprovisioning ?
I have to admit I lol'ed at this
As best I understand it as it was descibed by the company that analyzed these failed drives, a block of NAND flash either went bad or became inaccessible by the controller rendering the drives useless and unable to be accessed by normal means of hooking it up to a SATA or USB port. Two drives, different NAND (50 nm for the G1 and 34 nm for the G2), same failure mode.
Once again, this is not definitive, just my observations but to me, I think review sites need to be a little more cautious about how they qualify intel's reputation for quality and reliability because from my perspective, intel has neither and I have since began using crucial SSD's. Hopefully, I will see much longer life from these new drives.
So in other words, you are saying that because of your experience with TWO drives, that reviewers "need to be a little more cautious about how they qualify intel's reputation for quality and reliability", in spite of the fact that Intel drives are universally acknowledged to be the most reliable in the industry.
Obviously, you got a bad break on the drives you purchased, but things like that can happen, and if you want to change drives, try Samsung, because they also are establishing a reputation for above average reliability.
True, Intel is the reliable choice, but for consumer systems this is not necessarily the 'right' choice. My wife's system drive died last year (mid Aug), and I replaced it with a 60GB OCZ Solid3 which ran $80 on sale at the time ($100 retail). Today I can get a newer, faster, more reliable 60GB SSD for ~$50, which is ~1/2 of the cost per performance on the same size drive. Next year the 60GB drives will not halve again, but we are going to see something more like what we see with traditional drives where there is a base floor of, say, $40 for a 60GB drive, and then $50-60 for 120GB, and $75-100 for 240GB. In fact we are already beginning to see this sandwiching of prices. But because SSDs are simpler to make than HDDs (no motor, no actuator, etc.) the floor may actually be lower than what HDDs hit.
But my point is that for the same cost of your single drive I can re-purchase ~2-3x over the same period and still have saved money over the same time period, and get a massive upgrade in performance and/or size with each upgrade. And because everything lives as an image, it is just a matter of a few hours of down time to hike up to Microcenter and deploy the new drive.
Buying for stability makes sense in a mission critical environment, or in a slow moving or mature technology. But in a market that is moving so quickly, it really makes more sense to buy cheap and plan on replacing it in a year or two. Otherwise it is more like being attached to a boat anchor where your initial investment ties you to antiquated technology.
BTW, 1 year out and the Solid 3 still runs great.
Early MLC OCZ drives (Core?) 2 x 128GB & 1 x the smaller one (forget capacity) = all returned. Refund not given, so when RMA replaced, straight to Flea-bay, un-opened, I pity the buyers.
Intel 1 x X25M MLC 160GB, arrived DOA. Replacement sent quickly: 3 yrs later, not a hiccup. Running as an OS drive with databases in the background too. Installs were not as fast as hoped for, due to lower write performance, but no real complaints, and 160GB was a nice size.
Intel 1 x X25E SLC 64GB, really what you would hope for in terms of performance: Absolutely no problems to date. Same usage as X25M. Installs are lightening quick. Nothing to fault except capacity.
Kingston: 2 x MLC SSD Now V+ (100GB ?) Both failed within 6 months. Yet to return second one. Usage: CrapBook, email, general usage.
Patriot: 1x MLC Wildfire 240GB, waited until BSOD issue resolved before purchase, updated FW right from the start, fault-less to date. Usage: same as Intel drives above. Under SATA-2 I reckon the X25E is faster though. No space problems.
Hope that helps someone...
The technology needs to mature still.
Hard drives were the same way... (MFM/RLL: notorious for bad sectors out of nowhere,snail performance. IDE: getting better, bad sector problems starting to go away. SATA: Bad sectors are caused by YOU now =P Interface now outpaces theoretical maximum physical speed limit.)
In a couple of years, you all will be only complaining about the size of the chips and wish that they were the size of your thumbdrives.... =P
No manufacturer will offer a 5 year warranty if less then 99% of the drives will meet this criteria... it is expensive to RMA product that expire during the warranty period.