News
11/7/2008
08:52 AM
George Crump
George Crump
Commentary
Connect Directly
RSS
E-Mail
50%
50%

SSD's Latency Impact

In our last entry we talked about latency and what it was. We also discussed how storage system manufacturers are trying to overcome latency and performance issues of mechanical drives by using techniques like making the drives faster by using higher RPM drives, array groups with a high drive count, short-stroking those drives, wide striping those drives, and increasing the number of application servers

In our last entry we talked about latency and what it was. We also discussed how storage system manufacturers are trying to overcome latency and performance issues of mechanical drives by using techniques like making the drives faster by using higher RPM drives, array groups with a high drive count, short-stroking those drives, wide striping those drives, and increasing the number of application servers for improved parallelism.All of these techniques cost money, are not very green, and in many cases are more expensive than simply using SSD. Not to mention that they don't typically come close to SSD performance. The result has been the existence of standalone, purpose-built SSD solutions like those from Texas Memory Systems, Solid Data Systems, and Violin Memory, or the manufacturer adding SSD in a "drive-like" manner to its current storage systems.

The speed of SSD technology, especially DRAM, changes the latency focus away from the actual storage medium, as it has now been optimized, and onto the storage system's infrastructure, which is suddenly a lot slower than the storage media. For vendors that incorporate SSD into existing drive enclosures, the performance of the shelf itself becomes a problem, the performance of the processors in the controllers becomes a problem, and an incorrectly sized cache (too big or too small) becomes a problem.

Another factor is that the software load on the controller becomes an issue. For the past several years, storage manufacturers have been piling on features to the storage controller like snapshots, replication, data deduplication, and others. All of these features take computing resources away from responding to storage I/O requests, which worsens system latency.

The result is that while the SSD technology going into the solution may be fast, simply adding SSD to your storage system may not dramatically improve performance like it should. Standalone, purpose-built SSD systems offer lower latency because these vendors have built systems from the chip up that are designed to deliver on the low latency of SSD.

In our next entry, we will examine those differences and how storage manufacturers will need to alter their delivery of SSD technology. Then we will wrap up with capacity management on SSDs. At the cost of SSD technology, the only good SSD is a FULL SSD.

Join us for our upcoming Webcast SSD: Flash vs. DRAM...and the winner is?

Track us on Twitter: http://twitter.com/storageswiss.

Subscribe to our RSS feed.

George Crump is founder of Storage Switzerland, an analyst firm focused on the virtualization and storage marketplaces. It provides strategic consulting and analysis to storage users, suppliers, and integrators. An industry veteran of more than 25 years, Crump has held engineering and sales positions at various IT industry manufacturers and integrators. Prior to Storage Switzerland, he was CTO at one of the nation's largest integrators.

Comment  | 
Print  | 
More Insights
Register for Dark Reading Newsletters
White Papers
Flash Poll
Current Issue
Cartoon
DevOps’ Impact on Application Security
DevOps’ Impact on Application Security
Managing the interdependency between software and infrastructure is a thorny challenge. Often, it’s a “developers are from Mars, systems engineers are from Venus” situation.
Video
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2014-4725
Published: 2014-07-27
The MailPoet Newsletters (wysija-newsletters) plugin before 2.6.7 for WordPress allows remote attackers to bypass authentication and execute arbitrary PHP code by uploading a crafted theme using wp-admin/admin-post.php and accessing the theme in wp-content/uploads/wysija/themes/mailp/.

CVE-2014-4726
Published: 2014-07-27
Unspecified vulnerability in the MailPoet Newsletters (wysija-newsletters) plugin before 2.6.8 for WordPress has unspecified impact and attack vectors.

CVE-2014-2363
Published: 2014-07-26
Morpho Itemiser 3 8.17 has hardcoded administrative credentials, which makes it easier for remote attackers to obtain access via a login request.

CVE-2014-2625
Published: 2014-07-26
Directory traversal vulnerability in the storedNtxFile function in HP Network Virtualization 8.6 (aka Shunra Network Virtualization) allows remote attackers to read arbitrary files via crafted input, aka ZDI-CAN-2023.

CVE-2014-2626
Published: 2014-07-26
Directory traversal vulnerability in the toServerObject function in HP Network Virtualization 8.6 (aka Shunra Network Virtualization) allows remote attackers to create files, and consequently execute arbitrary code, via crafted input, aka ZDI-CAN-2024.

Best of the Web
Dark Reading Radio
Archived Dark Reading Radio
Sara Peters hosts a conversation on Botnets and those who fight them.