[SOLVED] Data drives on controller or on MB??


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Im about to buy cables for my new build but have run into a wall here - because...

 

 

I have a SuperMicro X7SPA-HF-D525 with ICH9R 6 port sata controller on board - and I also have a IBM M1015 controller card for up to 8 drives.

The total number of drives will be 8 in this build, 6 for data, 1 parity, 1 cache.

 

 

 

 

I am puzzled about what would be best, to run the 6 data drives off the MB or to run them off the controller?

My concern is the shortest possible spin up time before the drives are readable / writeable.

 

 

 

 

The optimum solution in my mind would be to use the controller solely for parity and cache, and then have the data drives directly off the MB. Reason is I might consider move to windows 8 server later when it's released, and then the ICH9R would support RAID5, wich is an option I would have to pay extra for on the IBM card.

Depending on the outcome it is not the same amount of cables I need for the final setup.

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The spin up times for the drives are going to be determined by the drives themselves, whether they're on the controller card or the board will not make a difference.

 

I personally have my parity drive and all but one of my data drives running off of an AOC-SASLP-MV8 controller. I have one disk of the array that I use only for backups of my computers and my cache drive, both of which are WD Scorpio Black 7200rpm laptop drives, hooked up to the ports on the motherboard.

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for 8 drives it makes no difference at all in your build.

 

you could put the 6 data drives on the MB or the M1015 and the parity/cache on the other. or any combo...

 

You could put all 6 data on the mobo and P/C on the m1015 so that it is easier to trace out what is what down the road when you have to do maintenance.  that route you only need one breakout cable..

 

You performance will be the same no matter how you slice that build.

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Actually would it?  The X7SPA-HF-D525 has a x16 pci-e at x4 electrical so wouldn't the fastest ports be on the MB if you go over 6 connections anyway?  That's what I've heard others say about the SASLP-MV8 since it is a x4 controller anyway - 6 drives and under full speed, > 6 drives slight reduction.  Since it is pci-e 2.0 maybe that doesn't apply though.

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Actually would it?  The X7SPA-HF-D525 has a x16 pci-e at x4 electrical so wouldn't the fastest ports be on the MB if you go over 6 connections anyway?  That's what I've heard others say about the SASLP-MV8 since it is a x4 controller anyway - 6 drives and under full speed, > 6 drives slight reduction.  Since it is pci-e 2.0 maybe that doesn't apply though.

 

With today's 5400-7900rpm spinning disks even 8 drives on a 4x slot will not saturate it. A 4x PCIe 2.0 slot has theoretical total bandwidth of 2 gigaBYTES per second.  Well above what 8 spinning disks can do even at 100% throughput on all 8 disks at once. SSDs are a different story.

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Correct.

 

6 consumer spinners at PCIe v2 4x should not saturate it.

 

I have an 8 drive hardware raid5 on the same board. it benches in the 500MB/s area. I think he will be ok.

 

 

But... My motherboard only have PCIe v1 X4 - in a X8 form factor.

How would the story be for that?

 

 

Another thing I have been considering, would it give me a lower usual Watt usage if I had the parity/cache on the MB and the data drives on the controller, would the controller power down when not in use?

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Correct.

 

6 consumer spinners at PCIe v2 4x should not saturate it.

 

I have an 8 drive hardware raid5 on the same board. it benches in the 500MB/s area. I think he will be ok.

 

 

But... My motherboard only have PCIe v1 X4 - in a X8 form factor.

How would the story be for that?

If you have this X7SPA-HF-D525 SuperMicro has it listed "6. 1 (x4) PCI-E 2.0 (in x16) slot" in key features so they must have changed it.
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Correct.

 

6 consumer spinners at PCIe v2 4x should not saturate it.

 

I have an 8 drive hardware raid5 on the same board. it benches in the 500MB/s area. I think he will be ok.

 

 

But... My motherboard only have PCIe v1 X4 - in a X8 form factor.

How would the story be for that?

If you have this X7SPA-HF-D525 SuperMicro has it listed "6. 1 (x4) PCI-E 2.0 (in x16) slot" in key features so they must have changed it.

 

 

I was sure it was a PCIe v1 X4 in a X8, but what do I know, I usually do business on Macs were ports and standarts are not a real problem, because mostly only Apples own certified products will fit inside  :-X

 

 

 

 

Anyway, with that question settled that it should not matter in what way I do it in terms of speed - then what about power use, would their be a benefit in using the on board connectors for p&c as they are the only two running most of the time?

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Anyway, with that question settled that it should not matter in what way I do it in terms of speed - then what about power use, would their be a benefit in using the on board connectors for p&c as they are the only two running most of the time?

Probably won't really make a difference not sure the M1015 would shut down when array isn't in use.  unRAID will spin down the drives automatically but I doubt the card will powerdown.  But maybe it is a feature in the firmware of the card.  Never checked for anything like that.  Also if it does make a difference the only drive that would actually benefit would be the Cache drive.  The parity is only used when writing (when no array problems) so if you use it like me write once read many the parity drive is the least used drive in the system.
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The card wont powerdown or sleep.

It is designed for enterprise use and is "always available".

 

 

Well, my wife would say "NOOO" (because of a slightly higher power bill) and I think "Sweet" :)

 

 

Thank you all for answering my questions, this thread is now officially solved

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