That is very interesting. Does anybody know if slot 4 has the 4X, I assume that's referring to lanes or is that architecture no longer valid, to get full speed on the PCIe SSD card?
When you say the SSD will operate at half speed 200MB/s I assume that is 200 MegaBytes/sec and not 200 Megabits. My understanding is the capital "B" is for Byte and a lower case "b" is bit. It seems quite often these symbols aren't used correctly in various specs I've seen.
With my 3x4TB Deskstar internal raid I have 4 partitions and the AJA System Test shows:
Raid Partition 01: Read=484.2 MB/s, Write=433.6MB/s
Raid Partition 02: Read=447.7 MB/s, Write=377.1MB/s
Raid Partition 03: Read=378.5 MB/s, Write=313.1MB/s
Raid Partition 04: Read=361.1 MB/s, Write=303.1MB/s
The decreasing speeds I believe to be because of the successive position moving inward on the platters of the raid partitions. I think the write speed being greater than read is due to the disk caches 32MB which buffers the data making the speed test thing it's writing faster than reading but that's me guessing. Anybody know why Write is faster than read.
From this data I figure each single 4TB drive is capable of around 125-150 MB/s depending on where on the platter it is working. This is where I really start to question the MB/s vs Mb/s. DNX 220 is 220 Mb/s right? So according to these results a single drive could handle 6 to 7 DNX 220 streams hypothetically which I know is not true. Besides the non contiguous files requiring the heads to jump around the platter slowing things down I just have never seen that kind of throughput of video media.
So bottom line are the units MB/s being sited Mega Bytes or Mega Bits? Sure seems like bits to me. Now regardless of the units question assuming the Aja System Test and the 200MB/s you are quoting about SSD sataII speed is based on the same units that would mean that the sataII SSD is just shy of twice the 4TB HItachi DeskStar speed is. That to me makes a big case for the PCIe Card based SSD with additional eSata ports. Am I making sense?
Posted by: bigfish@pacbell.net
| Reply via web post | • | Reply to sender | • | Reply to group | • | Start a New Topic | • | Messages in this topic (7) |
No comments:
Post a Comment