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eMLC Part 2: It’s About Price per GB

September 1, 2011 Leave a comment

I have had the chance to meet with several analysts over the past couple of weeks and have raised the position that with eMLC the long awaited price parity of Tier-1 disks and SSDs is virtually upon us.  I had a mixed set of reactions, from “nope, not yet” to “sorry if I don’t act surprised, but I agree.”  For the skeptics I promised that I would compile some data to back up my claim.

For years the mantra of the SSD vendor was to look at the price per IOPS rather than the price per GB.  The Storage Performance Council provides an excellent source of data that facilitates that comparison in an audited forum with their flagship SPC-1 benchmark.  The SPC requires quite a bit of additional information to be reported for the result to be accepted, which provides an excellent data source when you want to examine the enterprise storage market.   If you bear with me I will walk through a few ways that I look through the data, and I promise that this is not a rehash of the cost per IOPS argument.

First, if you dig through the reports you can see how many disks are included in each solution as well as the total cost.  The chart below is an aggregation of the HDD based SPC-1 submissions showing the reported Total Tested Storage Configuration Price (including three-year maintenance) divided by the number of HDDs reported in the “priced storage configuration components” description.  It covers data from 12/1/2002 to 8/25/2011:

Now, let’s take it as a given that SSD can deliver much higher IOPS than an HDD of equivalent capacity, and price per GB is the only advantage disks bring to the table.  The historical way to get higher IOPS from HDDs was to use lots of drives and short stroke them.  The modern day equivalent is using low capacity, high performance HDDs rather than cheaper high capacity HDDs.  With the total cost of enterprise disk at close to $2,000 per HDD, the $/ GB of enterprise SSDs determines the minimum logical capacity of an HDD.  Here is an example of various SSD $/GB levels and the associated minimum disk capacity points:

Enterprise SSD $/ GB

Minimum HDD capacity

$ 30

67 GB

$ 20

100 GB

$ 10

200 GB

$7

286 GB

$5

400 GB

$3

667 GB

$1

2,000 GB

To get to the point that 300 GB HDD no longer make sense, the enterprise price per GB just needs to be around $7/GB and 146 GB HDDs are gone at around $14/GB.  Keep in mind that this is the price of the SSD capacity before redundancy and overhead to make it comparable to the HDD case.

It’s not fair (or permitted use) to compare audited SPC-1 data with data that has not gone through the same rigorous process, so I won’t make any comparisons here.  However, I think that when looking at the trends, it is clear that the low capacity HDDs that are used for Tier-1 one storage are going away sooner rather than later.

About the Storage Performance Council (SPC)

The SPC is a non-profit corporation founded to define, standardize and promote storage benchmarks and to disseminate objective, verifiable storage performance data to the computer industry and its customers. The organization’s strategic objectives are to empower storage vendors to build better products as well as to stimulate the IT community to more rapidly trust and deploy multi-vendor storage technology.

The SPC membership consists of a broad cross-section of the storage industry. A complete SPC membership roster is available at http://www.storageperformance.org/about/roster/.

A complete list of SPC Results is available at http://www.storageperformance.org/results.

SPC, SPC-1, SPC-1 IOPS, SPC-1 Price-Performance, SPC-1 Results, are trademarks or registered trademarks of the Storage Performance Council (SPC)

Categories: Disk, Price, SPC, SSD

Texas Memory Systems reclaims performance crown and other Flash News

Yesterday TMS released the SPC-1 and SPC-2 results for the RamSan-630 system.  The results are very impressive and the press release goes into some depth.

The SPC imposes strict rules on how their results are presented, so in the interest of brevity I’ll only highlight two very significant items wrapped up in these results:

First, on a “cost for capacity” basis, the scales have tipped in favor of Flash vs. a disk-based system configured for maximum performance. “Cost for capacity” is not part of the SPC Reported Data but derived from SPC Reported data by dividing Total Price by Application Storage Unit (ASU) Capacity, which are both part of SPC Reported Data.

Second, the RamSan-630 produced highly competitive  SPC-2 bandwidth results.  This is significant because high bandwidth use cases have not been part of the traditional SSD discussion.  The typical argument goes, “SSDs are great at IOPS and disks are good for bandwidth.”  This is changing; SSDs are going to challenge disks anywhere that they are used for performance.  It no longer matters if you need random IO or streaming sequential IO; if performance is the primary criteria – SSDs will be the solution, period.

In other news, this week EMC announced that they were seeing demand for all flash configurations of VMAX and VNX (hopeful they will publish Storage Performance Council results!).  While I would encourage these clients to take a look at what a purpose built Flash system like the RamSan-630 can do; I do think that it clearly highlights where SSDs are going, from a “Tier-0” configuration to “Tier-1”.

Welcome to the future, EMC, glad you could join us.

SPC, SPC-1, SPC-2, are trademarks or registered trademarks of the Storage Performance Council (SPC).

Categories: Disk, SPC, SSD

The Real Price of Enterprise Storage

One of the pet peeves that come with the territory when deploying SSD systems is being compared to the price of consumer disks.  I might be bothered in particular because I have seen how rapidly the price has declined since Flash entered the field.   I remember that it was not very long ago (2004) that SSDs were thousands of dollars per GB!  Now, as the price of SSDs comes much closer to what high performance enterprise disk systems cost, the difference does not seem that bad to SSD veterans.

There is a general disconnect between what hard drives cost in the consumer market and what the disk based enterprise storage systems cost per GB.  I am sure that IT administrators get offers from end users all the time to personally buy a 1 TB drive for $80 to increase the size of their exchange mailbox.

So where can you find what enterprise storage systems cost?

The best source available is the Storage Performance Council’s (www.storageperformance.org) published data on the benchmark results of various enterprise storage systems, and one of the requirements is that the full costs must be disclosed.  When you look at this data in a few different ways you can draw some general conclusions. First, the obvious one, disks are rapidly getting cheaper per GB (below is some historical $/GB data on test results from systems with more than 100 disks):

However disks are not getting cheaper – they are just getting bigger.  Enterprise disks are very expensive once you include the costs of the storage controller, switching, and maintenance.  Below is the cost of a solution divided by the number of disks:

From these costs it is easy to see how there is a business case for deploying a solid state solution to eliminate 20 disk drives (or more).  You can always get more capacity with disks at a lower price point than SSDs and that will continue for a long time.  However, since the price per disk is so high, for smaller capacity, high performance workloads, SSDs are just cheaper.  The price point of a 15K RPM drive behind a storage controller is so high that you don’t have to be at the extreme end of the performance curve anymore to justify SSDs.

Realistically, once you are putting in 2-3 times as many drives for performance as you need for capacity, a serious investigation of SSDs should follow.

Categories: Disk, Price, SPC