Specifications, Pricing and Availability
We'll get the specs out of the way and then get into some real explanation as to what is going on with HighPoint's new switching HBA. HighPoint is offering switching technology in three controller cards at this time. The 2760 that we are looking at today is the tip of the sword, the flagship of the line-up. The two other models, 2744 and 2740 are nearly identical except the 2744 offers 16 external drive ports and the 2740 offers 16 internal ports for drives. The flagship 2760 that we are looking at today is the only 24 drive controller being offered with the technology that makes it possible to utilize all 16 lanes of PCIe bandwidth.
Looking at the specifications list, we see all of the normal enterprise features are there and nothing is out of the ordinary. Lots of maintenance, management and monitoring tools are present, just like what we see with other enterprise controllers. The one thing that is not present is an XOR engine. That makes the 2760 a software RAID controller; it uses some CPU horsepower to manage some tasks.
Now the fun part; the part we all want to know more about. The HighPoint RocketRAID 2760 uses 'switching architecture', but what does that mean? - Most of the newer HBAs on the market use a single chip-to-controller and manage all of the drives. If the number of drives outnumbers the number of channels a chip can handle, then expanders are used to divide the available bandwidth and that bandwidth is split. In the case of a 24 drive HBA, the signal is divided several times. Under normal circumstances dividing a 6 Gb/s signal isn't much of an issue since traditional hard drives do not require anywhere near 6 Gb/s. However, most hard drives aren't the Crucial RealSSD C300 and with it any serious enterprise class SSD that that will follow from this day forward. With this knowledge in hand, HighPoint set out to make something different, something that didn't require the 6 Gb/s signal to be divided.
It would be great to have a flow chart that showed the data path, but since we don't have one we will just use the card to lay things out. On the drive side we see the six SFF-8087 connectors that are used to connect four drives each. Each pair of SFF-8087 is directed to a single Marvell 88SE9485 controller chip. If you are doing the math then you already know that the controller would be capable of handling even more drives if HPT wanted to make such a beast. As we mentioned earlier, most controllers only use a single chip, even if it is configured to run 24 drives.
This is where the innovation comes in. The HighPoint RocketRAID 2760 uses four Marvell 88SE9485 chips and they are all held together with a single PLX bridge that allows all of the Marvell controllers to talk to a single PCIe 2.0 16 lane interface.
You might think such high end, exclusive technology would cost an arm and a leg, but that is where the XOR engine comes into it. To reduce costs XOR was left out and somehow HPT was able to deliver the 2760 at a price point of 699.99 at Newegg.
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