Promise Pegasus R4 8 TB
|Promise||Pegasus R4 4 TB||Pegasus R4 8 TB||Pegasus R6 6 TB||Pegasus R6 12 TB|
|Devices||4 x 1 TB||4 x 2 TB||6 x 1 TB||6 x 2 TB|
|Hard Drive||Hitachi 7K1000.D||Hitachi 7K3000||Hitachi 7K1000.D||Hitachi 7K3000|
The four-bay version of Promise's Pegasus is more affordable, offered in 4 and 6 TB configurations. You'll pay $1150 for the 4 TB R4 (versus $1800 for the entry-level 6 TB R6). Aside from its lower price and two-fewer drive bays, there's very little else distinguishing the R4 and R6 families. Promise even uses the same Hitachi Deskstar hard drives in them both.
Crack open the R4 and you find the same motherboard and power supply seen in the R6.
Eliminating two drive bays from the R6 does impact performance, though. In RAID 0, the R4's sequential reads top out at ~635 MB/s, representing a closet-to 33% drop from the R6. Sequential writes in RAID 0 only drop about 18%, from 635 MB/s to 535 MB/s.
RAID 1E and RAID 5 performance are mostly unchanged. The only exception is that sequential reads in RAID 5 peak at ~460 MB/s, about a 70% drop from the R6’s 780 MB/s.
What the R6 isn't expensive enough? :p Honestly, we couldn't include the ARC-8050 (http://www.areca.com.tw/products/thunderbolt.htm) because it's not readily available for purchase (yet).
with the external PCI-E device specification coming soon, i believe the days of thunderbolt are limited.
Thunderbolt IS ePCI-E. Well, using Intel's implementation. You think the specification will somehow make things cheaper? Nope.
Could you maybe do add a random read/write graph comparing GoFlex Desk with USB3 and Thunderbolt?
I was also wondering what the CPU usage is during read/write - is there any impact at all? or does the thunderbolt controller bear all the processing grunt-work?
Thanks again, great article.
The external PCIe will be cheaper and easier because it will be hosted directly by the mobo chipset, or the CPU by tapping into already existing hardware. Chip makers will not have to add a new and expensive tech to the device, the connection will just siphon off lanes that are already there. And because it is already standardized and cheap technology it will be easier and cheaper to implement. Finally it will be an open standard that multiple manufacturers can adopt. Thunderbolt (as much as I love the idea) is made and operated by Intel, and Intel wants to charge a premium for it. Until there are multiple chip makers who can make it, then it will continue to be too expensive... and when multiple chip makers can make it then Intel will be the only one worth buying (much like their network interfaces) because nobody can do quality like intel, but at least the price will come down.
And thunderbolt is not going optical fibre in the coming years. the cable is too expensive and cant carry much power.
and the fact that apple is using it gives some clues about its price, compatibility, usability and openness.
i remember how TB was promoted : one single wire from your PC to a TB brick. and from that brick you added USB, ethernet, firewire, DP, HDMI. basically it was touted as "1 wire for everything". supposed to be magical, and we all know how that turns out.
Read http://www.tomshardware.com/reviews/thunderbolt-performance-z77a-gd80,3205.html Thunderbolt can externalize anything. It just has to have the controller. It is external PCIe. External USB 3.0 and ethernet are possible but unlikely because they are already on the mobo.
From a practical standpoint, external PCIe may cheaper, but it's pointless from a performance standpoint http://en.wikipedia.org/wiki/PCI_Express#External_PCIe_cards. Everything is limited to a PCIe 1.0 x1 connection. The new ExpressCard standard (v2.0) ups bandwidth to slightly more than PCIe 1.0 x2, which still isn't that fast compared to TB (PCIe 2.0 x4 uplink). Plus ExpressCard only lets you connect a single device. It's one and done after that. For a mobile user, Thunderbolt is the way to go. Worse, you can't count on EC to be available. I'm already seeing Ultrabooks with TB. It makes sense because it doesn't require a lot of space. EC requires more space, hence it will be a greater rarity now that TB is out.
It looks expensive now but be patient. TB is something you will want. Many people need to look past the role Apple played. It clearly is a performance oriented technology that opens up a whole new world, especially on the mobile side.
Thank you for your Wikipedia quote. Everybody can quote from the spec sheet. The trouble is you make it seem like Intel are bunch of morons building a interconnect that nobody uses. That's is plain wrong. Just like SSDs, they will come down in price and next thing you know, you'll be asking yourself why in the world would I not use Thunderbolt. Imagine running a external GPU on your Retina Display MacbookPro when you dock your laptop. There'll be a lineup of people buying that technology at a premium price.
Partnering with Apple is no accident. 2 giant corporations backing the initiative is nothing to sneeze at. Give it a few years, and you'll soon find out the true power of Thunderbolt. USB 3.0 complements Thunderbolt.