Comments on: Flash talking – and a wee DRAM – with Texas Memory Systems http://storagemojo.com/2008/03/07/flash-talking-and-a-wee-dram-with-texas-memory-systems/ Data storage info & analysis Wed, 10 Mar 2010 12:27:38 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Robin Harris http://storagemojo.com/2008/03/07/flash-talking-and-a-wee-dram-with-texas-memory-systems/comment-page-1/#comment-179074 Robin Harris Sun, 09 Mar 2008 03:38:13 +0000 http://storagemojo.com/2008/03/07/flash-talking-and-a-wee-dram-with-texas-memory-systems/#comment-179074 PTZ - you're correct. Oops. Corrected the comment. Robin PTZ – you’re correct. Oops. Corrected the comment.

Robin

]]> By: PTZ http://storagemojo.com/2008/03/07/flash-talking-and-a-wee-dram-with-texas-memory-systems/comment-page-1/#comment-179068 PTZ Sun, 09 Mar 2008 02:25:57 +0000 http://storagemojo.com/2008/03/07/flash-talking-and-a-wee-dram-with-texas-memory-systems/#comment-179068 Agreed. About InfiniBand latency, you didn't read me correctly: I was talking about 1000 ns (or 1us), not 1 ms. Agreed.

About InfiniBand latency, you didn’t read me correctly: I was talking about 1000 ns (or 1us), not 1 ms.

]]> By: Robin Harris http://storagemojo.com/2008/03/07/flash-talking-and-a-wee-dram-with-texas-memory-systems/comment-page-1/#comment-179058 Robin Harris Sun, 09 Mar 2008 00:50:56 +0000 http://storagemojo.com/2008/03/07/flash-talking-and-a-wee-dram-with-texas-memory-systems/#comment-179058 That's why so many SDD firms have gone under over the years. It is a hard sell. I know. I took a crack at it back in the early 90s. And also why an SSD at $112/GB is a big deal. Network-based memory has advantages over a single system - you spread the cost and the benefits over more systems. Also, IIRC, Infiniband latency is <strike>quite a bit</strike> less than 1 <strike>ms</strike> µs, but I haven't looked at it for a few years. Robin That’s why so many SDD firms have gone under over the years. It is a hard sell. I know. I took a crack at it back in the early 90s.

And also why an SSD at $112/GB is a big deal.

Network-based memory has advantages over a single system – you spread the cost and the benefits over more systems.

Also, IIRC, Infiniband latency is quite a bit less than 1 ms µs, but I haven’t looked at it for a few years.

Robin

]]> By: PTZ http://storagemojo.com/2008/03/07/flash-talking-and-a-wee-dram-with-texas-memory-systems/comment-page-1/#comment-179055 PTZ Sun, 09 Mar 2008 00:28:10 +0000 http://storagemojo.com/2008/03/07/flash-talking-and-a-wee-dram-with-texas-memory-systems/#comment-179055 Woody Hutsell said: "[Our] RAM-based SSD is going to run about $650/GB." Hmm let's see I have the choice of buying his device at $650/GB, with a max throughput of 4 GB/s per link (4X DDR InfiniBand, FC would be less performant), and a latency of at least 1000+ ns (just counting the InfiniBand latency, not the additional overhead imposed by their device). Or I could run my app on a UPS-backed regular server with 128 GB of DDR2 667 ECC registered RAM [1] at 1/18th the price/GB [2], 2.7x the throughput [3], 1/5th the latency [4]. And create a RAM-drive or let the OS intelligently use the RAM as the filesystem buffercache (Linux is very good at it). Please someone give me a good reason I shouldn't go into this business and make big bucks by selling RAM at 18x its street price. [1] Like this 8 sockets, 64 DIMM slots, Opteron server: http://www.sun.com/servers/x64/x4600/specs.xml [2] $36/GB for DDR2 667 ECC registered 2 GB sticks: http://www.newegg.com/Product/Product.aspx?Item=N82E16820134328 [3] 10.7 GB/s for dual-channel DDR667 (667 (MT/s) * 128 (bits) / 8 (bits/bytes)) [4] ~200 ns of average latency in 4 and 8-socket HT configurations Woody Hutsell said: “[Our] RAM-based SSD is going to run about $650/GB.”

Hmm let’s see I have the choice of buying his device at $650/GB, with a max throughput of 4 GB/s per link (4X DDR InfiniBand, FC would be less performant), and a latency of at least 1000+ ns (just counting the InfiniBand latency, not the additional overhead imposed by their device).

Or I could run my app on a UPS-backed regular server with 128 GB of DDR2 667 ECC registered RAM [1] at 1/18th the price/GB [2], 2.7x the throughput [3], 1/5th the latency [4]. And create a RAM-drive or let the OS intelligently use the RAM as the filesystem buffercache (Linux is very good at it).

Please someone give me a good reason I shouldn’t go into this business and make big bucks by selling RAM at 18x its street price.

[1] Like this 8 sockets, 64 DIMM slots, Opteron server: http://www.sun.com/servers/x64/x4600/specs.xml
[2] $36/GB for DDR2 667 ECC registered 2 GB sticks: http://www.newegg.com/Product/Product.aspx?Item=N82E16820134328
[3] 10.7 GB/s for dual-channel DDR667 (667 (MT/s) * 128 (bits) / 8 (bits/bytes))
[4] ~200 ns of average latency in 4 and 8-socket HT configurations

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