Barry_Green
Moderator
It's commonly reported that P2 offloads to hard disks at either about "a gig a minute" or "2 gigs per minute." On an older powerbook G4, it seems to take about a minute per gig, or 16 minutes for a 16GB card. On a modern Windows laptop with the PCMCIA slot, it takes around 30 seconds per gigabyte, or 2 gigs per minute, or about 8:15 on my laptop to offload a 16GB card.
But -- does it need to be so? Could it be faster?
I got the idea from watching a 64GB P2 card be offloaded on a Mac Pro, using a PCD35 PCI-Express slot reader. It took barely over 10 minutes to offload a full 64GB card to a SATA RAID.
... and my Lenovo supports SATA, and two drives internally ...
So, yeah - I partitioned off a hunk of my internal C: drive into a new partition, and installed a second hard disk in the UltraBay. Using Windows' disk manager, I striped those two together and offloaded a chock-full 16GB card.
The result? A full 16GB card offloaded in 4:55. That's over 3GB per minute!
So then, I thought - hey, I've got an ExpressCard eSATA adapter and an external eSATA drive, so let's add that in the mix. So I re-did the RAID as a three-drive RAID. It helped, but only a little; it took 4:45 to offload the 16GB card. That's about 3.4GB/minute, or around 60 megabytes per second, which is closing in on the theoretical maximum of 80 megabytes per second that a P2 card is supposed to be able to support.
Now, if I had a 64GB card, I'm pretty sure that this three-drive RAID would probably hit the 800mbps promised speed, since that's what I've seen it do before.
Is this practical? No, not really - I don't know that I would want to be offloading my footage to RAID zero! But, it does go to show that the slower offload speeds aren't the card's fault, it can clearly be much faster. And this also shows why you can offload to two separate drives (such as an internal SATA and external USB) at full speed without sacrificing any performance... and that's probably a better way to make use of the card's speed.
In any case, it was pretty cool to configure a three-drive SATA RAID on a laptop... heh. If I'm ever asked to perform the world's fastest portable P2 offload, I think we now know how to make it happen. :thumbsup:
But -- does it need to be so? Could it be faster?
I got the idea from watching a 64GB P2 card be offloaded on a Mac Pro, using a PCD35 PCI-Express slot reader. It took barely over 10 minutes to offload a full 64GB card to a SATA RAID.
... and my Lenovo supports SATA, and two drives internally ...
So, yeah - I partitioned off a hunk of my internal C: drive into a new partition, and installed a second hard disk in the UltraBay. Using Windows' disk manager, I striped those two together and offloaded a chock-full 16GB card.
The result? A full 16GB card offloaded in 4:55. That's over 3GB per minute!
So then, I thought - hey, I've got an ExpressCard eSATA adapter and an external eSATA drive, so let's add that in the mix. So I re-did the RAID as a three-drive RAID. It helped, but only a little; it took 4:45 to offload the 16GB card. That's about 3.4GB/minute, or around 60 megabytes per second, which is closing in on the theoretical maximum of 80 megabytes per second that a P2 card is supposed to be able to support.
Now, if I had a 64GB card, I'm pretty sure that this three-drive RAID would probably hit the 800mbps promised speed, since that's what I've seen it do before.
Is this practical? No, not really - I don't know that I would want to be offloading my footage to RAID zero! But, it does go to show that the slower offload speeds aren't the card's fault, it can clearly be much faster. And this also shows why you can offload to two separate drives (such as an internal SATA and external USB) at full speed without sacrificing any performance... and that's probably a better way to make use of the card's speed.
In any case, it was pretty cool to configure a three-drive SATA RAID on a laptop... heh. If I'm ever asked to perform the world's fastest portable P2 offload, I think we now know how to make it happen. :thumbsup:
