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So these Port Multiplier cards that allow you to connect 1 port to 5 ports but with reduced speed between them, what I want to know is can the drives work as normal independent drives with different data/media stored on them or is that they pure RAID cards where they store the same data on them all?
They are not RAID cards, that would require an actual RAID card ;)
These act pretty much like a networking switch but for SATA/SAS drives. so yes the maximum bandwidth of the original port is shares between all the new ports. This shouldn't be a problem though, they intended for situations where speed comes second to number of drives and volume of storage.
You might have to watch out for compatability issues though, some controllers and RAID cards don't like them. Others fully support multiplier cards however.
So in an Windows OS environment, will it detect all the HDD's at once and allow you to access them anytime you like (with the reduced speed) or just the HDD that is "currently" selected?Quote:
Originally Posted by Funkstar
Reduced speed is fine, storage is my main aim.
How they are connected makes no difference to your windows experience. I'm not even sure if Windows will care how they connect, I don't know what level the port multiplication is carried out (Windows may or may not know or care about the multiplier in there at all).
Think of it like a USB hub. You don't have to select a peripheral to use one at a time, they all work and you can cascade hubs as well (up to 255 devices per master port). I don't think you can do that with SATA/SAS (although it wouldn't surprise me if you could), but you certainly aren't limited to one active drive at a time.
As for speed, in most situations you wouldn't ever notice the difference to be honest. Whatever bandwidth is being supplied by the master socket and multiplied out, is allocated to each device while data is being transferred to and from that device. So if you are pulling data from one drive on the multiplier card and copying it to another drive on a completely different master socket, you wouldn't see any difference. If you were copying data from one drive on the multiplier to another drive also on that multiplier, you might see a reduction in throughput. However that will depend on how much bandwidth your drives can actually use anyway. If the SATA port is capable of carrying more data than the drives can deal with, there will be less of a slow down.
All that is really theoretical anyway, in practice the time you would see biggest difference is if you were to use a port multiplier in conjunction with a RAID card and were hammering the array with transactions. Normal home use just to get more drives in your PC won't really be effected.
As a matter of interest, do you have a card in mind? Why do you need more SATA ports? and, wouldn't just having another SATA controller in there be better value?
I was looking at the Lycom ST 158 V2 and Lycom ST 126RM
But since I couldn't really find out much about these cards, I went with the Lycom 115
It's the best that I could find for the price and my budget, but could had done with 4 ports, but I only have one PCI-E x1 spot left, I already have a 3(4) port RAID card in my PCI slot.
I have 8 SATA drives, 2 Hot Swaps drives, 1 DVD drive with room for one more SATA drive in my case, finally two IDE drives.
All this is to store Anime. :)
I really should setup a server, but am stubborn and like everything together.
I would say you are right to keep it simple and just go with another SATA controller.
thanks for the links though, I didn't know Lycom did those two multiplier cards, I think I'm going to experiment with one to see how well, or indeed if they work with my RAID card (a hardware Dell PERC 5/i and a PERC 6/i) when I eventually get my server up and running.
If you go ahead and purchase any of them, please reply back/new topic on how it went, I'm still very interested in them for a later project.Quote:
Originally Posted by Funkstar