LSI SAS 2008 vs IBM MegaRaid MR10i (LSI SAS 1078) - Which to use

[Rototype]

Hi,

I'm just going to be rebuilding my NAS box with a new motherboard (SuperMicro H8DG6-F) which has a LSI 2008 SAS controller onboard but from my previous configuration I also have an IBM MegaRaaid MR10i which is based on the LSI 1078 chipset. There's 6 SATA onboard and I have a 5-way hot-swap drive cage with additionally 1 x bulk dump drive (5TB WD Red)) 2 x cache drives (256GB SSD, samsung 2.5) and 2 x boot drives (16GB SSD thin small) along with a LSI Nytro WarpDrive 1.86TB that sits in a PCIe-X8 slot which will probably be used for video buffering. The 5 drives in the cage are 6TG WD Red.

I don't actually need all of the ports off both SAS cards (I'll probably have a few ports spare anyways) but I'm wondering if I'd be getting any advantage in using the IBM card over the onboard SAS controller? Basically is a LSI 1078 any faster or more compatible than a LSI 2008? As far as I can see they're both 3GB/s and would (looking at the block diagram of the motherboard) both be coming from pretty much the same place. My only thought would be that depending on which PCIe socket I install it in I could be attaching to the second CPU and reducing the load on the first CPU - would this have any performance benefit?

The NAS is primarily for use as a home system so absolute performance wouldn't be that critical, it's just that if one solution is better than the other I'd like to put it that way now to save having to do it all over again later. Also, would there be any issues with having both adaptors in the system together? Another option I could use is to feed the SAS output from one or other of the cards to an external drive array for future expansion and possibly a backup drive (tape library).

Rototype

 

[jgreco]

No, avoid the 1078. It is a first-gen SAS controller and has some issues, including a cap of 2^32-1 for LBA which typically limits you to a 2.2TB drive size. Those haven't been recommended in a decade.

No idea what "3GB/s" means in this context. Are you talking SAS link speed? PCIe link speed? (both of which are measured in bits/s, not bytes/s) Or transfer speed? Because the 2008/2308 is a SAS 6Gbit/sec controller.

https://www.ixsystems.com/community/threads/confused-about-that-lsi-card-join-the-crowd.11901/

 

[Rototype]

No, avoid the 1078. It is a first-gen SAS controller and has some issues, including a cap of 2^32-1 for LBA which typically limits you to a 2.2TB drive size. Those haven't been recommended in a decade.

No idea what "3GB/s" means in this context. Are you talking SAS link speed? PCIe link speed? (both of which are measured in bits/s, not bytes/s) Or transfer speed? Because the 2008/2308 is a SAS 6Gbit/sec controller.

https://www.ixsystems.com/community/threads/confused-about-that-lsi-card-join-the-crowd.11901/

Thanks for that, I did mean 3Gbit/s (typo) which is what I'd been told they both were. Looks like I'm using the onboard (2008) then... (with the 2.2TB limit on the 1078 that rules it out completely since all of the major drives are 5 or 6TB each. Know anyone who wants a cheap IBM MR10i?)

This is the major reason I asked this question here where there are people who know this stuff. I'll have a good look at that link, I might need another one if I want to go external at some point. Is it possible to have 2 x 2008 HBAs in the same system? I'll keep looking at existing posts to see if I can answer this myself.

Thanks again

Rototype.

 

[jgreco]

Perhaps also useful:

https://www.ixsystems.com/community/resources/dont-be-afraid-to-be-sas-sy.48/