In preparation of the release of our latest Host Bus Adapter (HBA) – the LightPulse® 16Gb Fibre Channel (16GFC) – we took a look at its performance and were pretty amazed by the results compared to our previous gen product. The LPe16002 is of course capable of running 16GFC, so you would expect performance to be about double that of 8GFC, but then again, when you dig into the details of the 16GFC spec, you may be disappointed to find out that your data bits aren’t actually flying over the wire at double the speed compared to 8GFC. 16GFC actually runs at 14.025Gbp/s baud rate where 8GFC runs at 8.5 so it’s slower right? Wrong! The designers of the specification did a clever thing when they came up with 16GFC. All previous speeds used a 8b/10b encoding scheme, meaning that for every 10 bits flying over the wire, 8 of them are data and 2 are used to make sure the data is correct, so only 80% of the bits are your data. For 16GFC, they changed the encoding to a much more efficient 64b/66b scheme, so much less of the bits are wasted for coherency, and a bigger chunk of it is your data. So the bottom line is that 16GFC link rate delivers twice the data deliver over 8GFC.
But saying the new LPe16002 HBA can deliver twice the performance over 8GFC HBAs is the expectation, but there is much more to the story. So sure, as you can see in figure 1, the 16GFC LPe16002 HBA is capable of 1576MB/s compared to 789MB/s for our 8GFC LPe12002 HBA, almost exactly double. The LPe16002 is the first HBA with an 8-core processor and can deliver performance that is actually 5x that of previous adapters.
Figure 1.
Max I/O per second (IOPS) for a single port of the LPe16002 is just over 1 million! This is one area where the 8-core processor shines, it has the ability to crank out millions of I/O processing instructions when the data size isn’t too burdensome. At this small data block size that we measure, this kind of performance is all about the HBA processor performance and not the link rate, this HBA would be capable of 1 million IOPS even at 8GFC…..that’s right, you can get this kind of IOPS without having to buy a new 16GFC switch.
Figure 2.
Ok, I know what you’re thinking….”My application doesn’t use 512 byte data blocks”. Good point, the fact is that the highest transaction applications actually use mostly 4k or 8k data blocks and that area is another measure of the muscle that the LPe16002 has. Most HBAs cannot reach the link rate maximum until the data blocks get very large, usually around 16k data block sizes, so I/O transactions for database applications can be limited by the HBA processor and can’t get close to the Fibre Channel link rate ceiling. This is not the case with the LPe16002, because its massive power allows for near link rate performance at 4k and 8k data blocks.
Like previous generations of Emulex HBAs, they are backwards compatible and leverage a common driver stack. This means that you can buy a LPe16000 HBA today and plug it into your current server alongside our previous products and connect the card into your current 4 or 8GFC switch. You will not be able to utilize the full size of a 16GFC link until you upgrade your switch, but that doesn’t mean you won’t see other massive performance benefits like lower I/O response times and higher transaction rates. To see proof of this and a full performance demo, see the LPe16000 performance demonstration video.
Figure 3.
The purpose of our blog are to facilitate an ongoing conversation on what's going on in our industry, with our partners and customers. We encourage your comments. Your ideas and feedback are what makes our blogs interesting, timely and useful for our readers.
We want to publish your comments, however, all comments are moderated. Offensive, off-topic or fraudulent comments won't be approved. We also expect a basic level of civility; disagreements are expected, but mutual respect is a must. We will not post comments that contain vulgar or abusive language; personal attacks of any kind; or offensive terms that target specific ethnic or racial groups. Comments that make accusations will also not be posted.
By submitting a comment, you agree to these terms; having your name displayed with your comment and that you are 18 years old or older. Your name and personal information will not be used for any other purpose, and your e-mail address will not be published.