Violin Announces Memory Appliance Server

Published: December 13, 2007

by Timothy Prickett Morgan

A startup company called Violin Scalable Memory has just come out of stealth mode this week, and has announced a partnership with Advanced Micro Devices at the same time it is putting a memory appliance for servers onto the market.

Violin was founded in March 2005 by Donpaul Stevens, who is the company's chief executive officer, and Jon Bennett, the company's chief technology officer. Both hail from FORE Systems, a 1990s networking company that was acquired by British electronics firm GEC, which was acquired by Italian electronics firm Marconi, which was in turn acquired by Swedish telecom giant Ericsson. Both have worked at a number of startups since those days, and got together to create a set of appliances based on main memory and flash memory to help speed up various kinds of applications running on servers these days. Violin, which is based in Iselin, New Jersey, stared doing its technology trials in November 2006 and started quietly rolling out its first product, the Violin 1010 Memory Appliance, in August. To date, the company has raised $11 million in venture capital, and believes that it can carve out a nice niche for itself for companies that have memory and I/O intensive applications where disk just isn't cutting it. (Incidentally, the name "Violin" has nothing to do with memory or appliances. Stevens happened to be listening to music when he was thinking of a company name, and realized it has "IO" in the middle of the word.)

Companies have a lot of ways to get data to their servers, but as processors get faster, even the fastest disks have not been able to keep up. According to Morgan Littlewood, vice president of marketing and business development at Violin, it takes around 10 milliseconds to get data out of a disk array into a server; in clustered server environments, where data is passed from machine to machine (sometimes from cache memory, sometimes from main memory); it can take 50 microseconds if you use a high-speed interconnect. And if you move to multicore machines and try to set up a virtualized cluster on a relatively small number of machines, virtual memory is slow and the physical memory capacity in a server, which can top out at 32 GB or 64 GB for a regular two-socket, eight-core server these days, is too low for the workloads.

While a number of companies have tried to put solid state disks in the market, shooting the gap between slow disk performance and low cost and main memory high performance and high cost, SSD has not really taken off. That's not just because it is expensive, but because companies want to deploy what Violin calls memory appliances in a number of different ways. For some applications, having a memory appliance hook to a network of servers as a block-level device is a great thing, and can significantly boost performance of applications. (Think of the Web caching servers and services out there on the Internet.) But for other applications, what a customer needs is something that can extend the main memory in a server itself--radically expanding the amount of main memory that the server can address directly. And in still other cases, main memory is too hot or too expensive and a device based on flash memory is a better option. The Violin 1010 Memory Appliance will eventually do all three.

To create its memory appliance, Violin is trying to keep the price as low as possible, the heat as low as possible, and the memory density as high as possible. To that end, the company is using DDR2 main memory, and is sticking with relatively inexpensive, low capacity 1 Gbit memory chips. While Fully-Buffered DIMMs allows more main memory, the amount of power that FB-DIMM draws is twice that of a similar capacity as DDR2 main memory. So forget that. But that doesn't mean the Violin appliance can't support FB-DIMM or any other kind of electronic storage behind its Violin Switched Memory, nicked-named VXM, controller. To keep the price as low as possible, the Violin Intelligent Memory Modules (VIMMs) that plug into the appliance as based on the same 5.25-inch DDR2 memory sockets in a standard server, and Violin packs a lot of memory and a three-port switched memory controller onto the chip thanks to the fact that the memory controller industry has machinery that can make a DIMM that is 2.75 inches high. The Violin 1010 Memory Appliance has 84 of these memory modules, which range in size from 2 GB to 6 GB, which gives the appliance a memory capacity that ranges from 120 GB to 504 GB--all fitting into a 2U chassis and burning about 360 watts of power using regular DDR2 main memory. Eventually, a similar appliance based on NAND flash storage will follow it to market, with a memory module ranging from 32 GB to 64 GB and a total appliance capacity ranging from 1 TB to 5 TB. This flash memory appliance is in lab trials now, with volume shipments expected in the first half of 2008.

Littlewood says that the memory appliance using DDR2 technology can deliver about 3 million I/Os per second (IOPs) with an average latency of 3 microseconds. This device has about six times the density of a 2U server loaded up with main memory, and a 42U rack of appliances has 8 TB of memory. The flash variant of the appliance will be able to deliver about 100,000 IOPs of data with a 50 microsecond latency, which is 100 times the performance of a disk array; up to 80 TB of flash data will fit in a rack with 24 of these appliances, which will use a lot less power and generate a lot less heat, too.

Here's where it gets interesting. As part of the partnership announced this week with AMD, the two companies are going to work together to allow the Violin memory appliance to plug into a HyperTransport link, just like real main memory in a server does. In this case, the Violin appliance will plug into an HTX port on a server, and as far as any of the processors in the server are concerned, that memory appliance will look, feel, and act just like main memory in that server. This support is expected sometime in the second half of 2008, and you can bet a lot of customers will be looking for such a device to boost performance. Violin has already announced its intention to support access to the device using RDMA protocols over InfiniBand and 10 Gigabit Ethernet using OpenFabrics protocols, too.

Pricing for the Violin 1010 Memory Appliance is a bit of a trade secret, but Littlewood says that a device with 21 VIMM modules and 120 GB of capacity (that capacity is weird because the main memory is actually given RAID data protection, too) for under $50,000.