Basic Statistics of Various Readily Available Flash SSD Models
Model	Capacity (GB)	Drive Market Price	Linear Read mb/sec	Linear Write mb/sec	Random Access Time millisec
2.5" 15,000 rpm SAS Hard Disk	36	350	110	110	4.00
2.5" 7,200 rpm SATA Hard Disk	200	150	70	70	15.00
Mtron Mobi 32gb	32	643	110	80	0.04
Mtron Mobi 64gb 3.5"	64	1,216	110	80	0.04
Mtron Pro 32gb	32	805	120	90	0.04
Mtron Pro 64gb	64	1,517	120	90	0.04
MemoRight 32gb	32	879	100	100	0.10
MemoRight gt 64gb	64	1,989	120	120	0.10
MemoRight gt 128gb	128	3,539	120	120	0.10
SuperTalent 32gb MLC	30	299	120	40	0.50
SuperTalent 64gb MLC	60	479	120	40	0.50
SuperTalent 128gb MLC	120	669	120	40	0.50
Mtron Mobi-1000 32gb MLC	32	290	100	40	0.04
Mtron Mobi-1000 64gb MLC	64	476	100	40	0.04
MLC CF 32gb kit	32	179	35	17	0.20
Proprietary 32gb MLC	32	179	100	30	0.40
Addonics PCI MLC CF 64gb kit	64	329	35	17	0.20

Computing Random Read and Write IOPS

In the following table, we compute random read and write rates per second based upon the data in the preceding table, as well as data generated from our own testing and data ferreted out over the internet.

Data regarding random read times is easily computed. All one needs to do to compute the random reads of a particular size is to divide the linear speed by the size of the block, add in the access time, and then convert the total from a microseconds elapsed time to a quantity per second.

Similarly, the random write times for MFT are easy to compute. All one has to do is to divide the linear write speed by the block size. Test after test has established that MFT performs at the published linear write speed of the drive provided this is reported correctly, because MFT writes in erase block increments.

Regarding actual native performance random writes, results for Mtrons and for CF cards are based upon results determined by EasyCo. Results for Memo Right are based upon tests reported on the Internet. Results for SuperTalent are based upon known general limits of MLC Flash media, as well as inferences. Here, we may have been slightly too generous.

Computed or Reported Raw Performance of Various Flash Models
Model	8k Random Rds/sec	16k Random Rds/sec	8k Random Wts/sec	16k Random Wts/sec	8k Random Wts/sec w/ MFT	16k Random Wts/sec w/ MFT
15,000 rpm SAS Hard Disk	250	250	250	250	n/a	n/a
7,200 rpm SATA Hard Disk	70	70	70	70	n/a	n/a
Mtron Mobi 32gb	8,871	5,392	123	123	10,000	5,000
Mtron Mobi 64gb 3.5"	8,871	5,392	123	123	10,000	5,000
Mtron Pro 32gb	9,375	5,769	123	123	11,250	5,625
Mtron Pro 64gb	9,375	5,769	123	123	11,250	5,625
MemoRight 32gb	5,556	3,846	271	234	12,500	6,250
MemoRight gt 64gb	6,000	4,286	271	234	15,000	7,500
MemoRight gt 128gb	6,000	4,286	271	234	15,000	7,500
SuperTalent 32gb MLC	1,881	1,752	64	62	750	375
SuperTalent 64gb MLC	1,881	1,752	64	62	750	375
SuperTalent 128gb MLC	1,881	1,752	64	62	750	375
Mtron Mobi-1000 32gb MLC	8,333	5,000	25	25	5,000	2,500
Mtron Mobi-1000 64gb MLC	8,333	5,000	25	25	5,000	2,500
MLC CF 32gb kit	3,043	1,795	3	3	2,125	1,063
Proprietary 32gb MLC	2,083	1,786	15	15	3,750	1,875
Addonics PCI MLC CF 64gb kit	3,043	1,795	3	3	2,125	1,063

Use of Microsoft Exchange Server Benchmarks
as the Basis for Assessing Overall Performance

Microsoft publishes a detailed testing protocol for its Exchange email and collaboration Server. In the broadest sense, this test based upon common usage patterns, recognizes that about 30% of Exchange's activity is write activity, while 70% is read activity. Similarly, it recognizes an average read or write size of about 11,000 bytes, which can be expressed (more or less) as the average of two 8k elements of activity and one 16k element (average element size 10.66kb). All of our performance estimates have been based upon that standard and mix of reads/writes and data sizes.

While one might choose another standard for comparison, the key advantages of the Exchange standard are (a) that it applies to a very large number of servers in its own right, and (b) because many other servers which we might wish to consider (e.g. database servers) would result in close but less conservative numbers. Conservative numbers are always desirable to prevent under-engineering.

Consideration of the Performance Results and Costs of Bare Flash Drives

The following table shows the essential description and price information of the Flash Drives previously discussed. It then computes the average IOs per second, based upon the Windows Exchange Server measure.

From this, we see that the best of SLC flash drives - the Mtron and MemoRight SLCs - perform at IOP rates that are superior to the fastest Hard Disks by a significant measure. In the case of the Mtrons, the product is overall 60% faster, while in the case of the MemoRights, it is about three times as fast as a 15k rpm SAS drive.

On the other hand, we can see by looking at the price, price per gigabyte, and price per IOPS that both the Mtron and the MemoRight are significantly more expensive than a premium Disk Drive, being 2x to 3x more expensive, though not dissimilar on a per IOPS basis.

Similarly, if we consider the MLC drives by themselves, we see that these are a lot less expensive - often at only a third of the cost per drive and per gigabyte. But we also see that the IOPS performance is not all that good - effectively a little bit slower than a 7200 rpm drive, and about 1/5th to 1/10th of the Mtron and MemoRights. We see this reflected in the cost per IOP where the MLC drives are typically around twice the IOPS cost of a well founded SLC drive.

A Note About the IOPS-Gig Measure

Earlier, we expressed two common measures of assessing the cost or value of products: the cost per gigabyte and the cost per input-outputs per second (IOPS). One extremely useful measure to assess the relative value of a product combination is what we call the IOPS-Gig. This divides the total cost by the number of usable gigabytes and then further divides the result by the number of IOPS per device. The resulting value is expressed in mils (tenths of a cent). Thus, in the case of a 15k SAS drive, 39 mils times 250 IOPS a second times 36gb of space results in 351,000 mils, or $351.

The value of IOPS-Gigs is that they give you a general appreciation of the overall value of the solution, what ever its technical advantages vis-a-vis a given mix of IOPS and space. We see this in the comparison between the 15k SAS drive and the 7200 rpm drive. We see there is an approximate difference of 3.5:1 in IOPS-Gigs, and we realize that we do not assess these products purely by their relative cost which is 13:1 in terms of cost per gigabyte, and rather apply some sort of qualitative modifier (IOPS) to both prices.

You will note in this that while bare Flash Drives are not hugely dissimilar in IOPS-gigs, both are dramatically different from the IOPS-gig results obtained with MFT

Cost and Performance Conclusions for Various Flash SSD Models by Themselves
Model	Capacity in GB	Drive Market Price	MS Exchange IOPS	Price per gig	IOP Price	Mils per IOPS-Gig
2,5" 15,000 rpm SAS Hard Disk	36	350	250	9.72	1.40	39
2.5" 7,200 rpm SATA Hard Disk	200	150	70	0.75	0.75	11
Mtron Mobi 32gb	32	643	394	20.09	1.63	51
Mtron Mobi 64gb 3.5"	64	1,216	394	19.00	3.08	48
Mtron Pro 32gb	32	805	395	25.16	2.04	64
Mtron Pro 64gb	64	1,517	395	23.70	3.84	60
MemoRight 32gb	32	879	763	27.47	1.15	36
MemoRight gt 64gb	64	1,989	771	31.08	2.58	40
MemoRight gt 128gb	128	3,539	771	27.65	4.59	36
SuperTalent 32gb MLC	30	299	195	9.97	1.53	51
SuperTalent 64gb MLC	60	479	195	7.98	2.46	41
SuperTalent 128gb MLC	120	669	195	5.42	3.43	29
Mtron Mobi-1000 32gb MLC	32	290	83	9.06	3.51	110
Mtron Mobi-1000 64gb MLC	64	476	83	7.44	5.76	90
MLC CF 32gb kit	32	179	11	5.59	15.84	495
Proprietary 32gb MLC	32	179	50	5.59	3.61	113
Addonics PCI MLC CF 64gb kit	64	329	11	5.14	29.11	455

The Superior Performance of an MFT Enhanced Drive

The next table shows the same basic data as before, but reflects both the additional cost of adding MFT software, and on the other hand the dramatic increase in IOPS that MFT provides. This increase in speed is most apparent in the Mtron Flash media, because Mtron is well renowned for its extremely high random read speed, which complements the high random write performance of MFT.

The first thing to note, even from the first pricing element, is the dramatic improvement in performance with MFT. The quite good performance of the Mtron jumps almost 20-fold, to a point where it is 30 times faster than the fastest hard disk made. Similarly, MFT enabled drives are 10 times faster than the fastest current technology - the MemoRights.

But the most important thing to note regarding the Mtron and MemoRight items is that this has not been done at high cost. In general, the cost per IOPS of the SLC drives is barely 1/10th of the previous bare-drive IOPS costs.

The most notable general point of the table is the vast improvement in the performance of MLC drives. These incur a speed improvement of over 50-fold, and in the case of drives made from CF cards, almost 100-fold. As a result, the cost per IOPS of these falls below that of SLC drives, while the price per gigabyte of these is half that of an SLC drive. This is important to remember because the base cost of MLC media is expected to decline by at least two-thirds over the next three years.

A Note About MFT Pricing

You will note that there are two different base prices here for MFT. MFT has a pricing level for MLC drives that is half that of SLC drives. Similarly, the server variant of MFT is priced per 32gb of net usable storage space. MFT does not charge for parity or mirror drives. This is reflected in the price shown, which reflects the assumption that MFT will only get used in about three out of four drives of a drive array. The actual price of MFT may be lower based upon the storage array design, as well as the vendor providing product.

Cost and Performance Conclusions for Various MFT Enabled Flash SSD Models Used in a Server Environment
Model	Capacity in GB	Drive Market Price	MFT Allowed Cost	MS Exchange IOPS	Price per gig	IOP Price	Mils per IOPS-Gig
2.5" 15,000 rpm SAS Hard Disk	36	350	n/a	250	9.72	2.58	39
2.5" 7,200 rpm SATA Hard Disk	200	150	n/a	700	0.75	1.20	11
Mtron Mobi 32gb	32	643	375	7,341	35.35	0.14	5
Mtron Mobi 64gb 3.5"	64	1,216	750	7,341	34.13	0.27	5
Mtron Pro 32gb	32	805	375	7,931	40.97	0.15	5
Mtron Pro 64gb	64	1,517	750	7,931	39.36	0.29	5
MemoRight 32gb	32	879	375	5,648	43.54	0.22	8
MemoRight gt 64gb	64	1,989	750	6,281	47.55	0.44	8
MemoRight gt 128gb	128	3,539	1,500	6,281	43.74	0.80	7
SuperTalent 32gb MLC	30	299	187	4,705	17.58	0.10	4
SuperTalent 64gb MLC	60	479	375	4,705	15.38	0.18	3
SuperTalent 128gb MLC	120	669	750	4,705	12.53	0.29	3
Mtron Mobi-1000 32gb MLC	32	290	187	5,463	16.58	0.09	3
Mtron Mobi-1000 64gb MLC	64	476	375	5,463	14.77	0.16	3
MLC CF 32gb kit	32	179	187	2,116	12.73	0.17	6
Proprietary 32gb MLC	32	179	187	2,166	12.73	0.17	6
Addonics PCI MLC CF 64gb kit	64	329	375	2,116	12.22	0.33	6

MFT for Laptops and Workstations

The workstation variant of MFT is much less expensive than the server version. The retail price of MFT for drives of any size used in Laptops or Workstations is just $149. The price shown reflects pricing of Internet sellers for such products. Here, while we see the dramatic performance gains of MFT, we also see the same reflected in prices that are very interesting.

Cost and Performance Conclusions for Various MFT Enabled Flash SSD Models Used in a Laptop or Workstation Environment
Model	Capacity in GB	Drive Market Price	MFT Allowed Cost	MS Exchange IOPS	Price per gig	IOP Price	Mils per IOPS-Gig
2.5" 15,000 rpm SAS Hard Disk	36	350	n/a	250	9.72	1.70	39
2.5" 7,200 rpm SATA Hard Disk	200	150	n/a	700	0.75	0.34	11
Mtron Mobi 32gb	32	643	129	7,341	24.62	0.11	3
Mtron Mobi 64gb 3.5"	64	1,216	129	7,341	21.44	0.09	3
Mtron Pro 32gb	32	805	129	7,931	29.78	0.12	4
Mtron Pro 64gb	64	1,517	129	7,931	26.24	0.10	3
MemoRight 32gb	32	879	129	5,648	32.14	0.18	6
MemoRight gt 64gb	64	1,989	129	6,281	33.77	0.17	5
MemoRight gt 128gb	128	3,539	129	6,281	29.24	0.15	5
SuperTalent 32gb MLC	30	299	129	4,705	14.56	0.10	3
SuperTalent 64gb MLC	60	479	129	4,705	10.34	0.07	2
SuperTalent 128gb MLC	120	669	129	4,705	6.62	0.04	1
Mtron Mobi-1000 32gb MLC	32	290	129	5,463	13.36	0.08	2
Mtron Mobi-1000 64gb MLC	64	476	129	5,463	9.65	0.06	2
MLC CF 32gb kit	32	179	129	2,116	9.82	0.15	5
Proprietary 32gb MLC	32	179	129	2,166	9.82	0.14	5
Addonics PCI MLC CF 64gb kit	64	329	129	2,116	7.30	0.11	3

MFT versus Zeus IOPS

As was noted at the beginning, the Zeus drive, by equivalent calculation, performs random IO of the size specified at about twice the speed of the MFT when used with SLC media, but a cost typically ten times as high. This is due in significant part to Zeus's transfer time which is 220mb/sec linear read and 115mb/sec linear write, as well as a random access time reported to be 20 to 100 microseconds, with a presumed average of around 25 microseconds.

Two points should be made about this. The first is that there are absolute limits to what any server can accept. The fastest time achieved so far has been 71,000 8kb random reads, or 541mb/sec on a 21 drive array. This is only 39% of the theoretical maximum for the same number of Mtron Mobi drives. It points out the obvious that computers and disk controllers have finite limits regarding the data they will accept. By comparison, our own tests showed that four drives could reach a rate of more than 30,000 8k reads, while 8 drives could exceed 40,000 8k reads. The practical point here is that there is only so much data that can be pumped into a Buss. Similarly, there is only so much data that can be pumped through an iSCSI, Fibre-Channel, or Infiniband network. Whether that point is reached with six or seven Zeus products or a larger number of something else, there is a point that cannot be exceeded.

Similarly, the size of needed storage should be considered. One can attain speed either through single big elements, or several smaller elements. But if one needs large amounts of storage as well as speed, paying for absolute speed rather than incremental speed makes little sense. For instance, if one needs two terabytes, one must practically engineer with 16 128gb drives, and whether these drives operate at 8,000 8k random reads a second or 4,000 random reads a second has little practical difference as both will hit the throat limit of 70,000 transactions a second.