Onboard Raid 5 vs. Adaptec PCIE

[mike909]

Wondering if anyone has any idea on which would perform better? This Mobo has onboard raid 5 via the NVIDIA MCP61P chipset, and this Adaptec Card is a pcie 4x add-on card for raid 5.
Anyone have any idea, performance wise, if one would be better than the other? The adaptec card is 300$, the mobo w/ on-board raid controller is 70$. Also, in case of controller failure, would I be better off with adaptec card vs. onboard? (my guess is doesn't matter).

[redwudz]

I would suspect the Adaptec card would be the better performer. It's hard to say how much CPU overhead the motherboard controller would use. Maybe none, but the same question would be there for the MCP61P chipset. Unless all it does is RAID, (Which I doubt) it may slow down your system and defeat any speed gains you might see from a RAID setup.

RAID 5 is certainly a better setup than RAID 0, but still overkill for most of us, with medium write performance and needing a minimum of 3 HDs. You would still need an additional drive(s) or RAID array to improve the speed of data handling when using the computer for editing or somewhat less, encoding. All my systems have a minimum of two hard drives.

RAID 5 info: http://www.pcguide.com/ref/hdd/perf/raid/levels/singleLevel5-c.html

[mike909]

Thanks for the info. This system would act purely as a NAS; which will store video project files, and other Multimedia files to be streamed to HTPC. It won't be doing anything but file serving (probably with NasLite) The RAID 5 is for redundancy (can't lose project files if a drive dies) and the 500gig sata-300 drives are getting cheaper by the day, so I was figuring on 4 of them for a 1.5tb total.
I tend to agree with you that the MCP61P will be doing more than just raid controlling, so will end up degrading performance of the array, just wish there was some sort of comparison of the two setups.

[redwudz]

For your application, RAID 5 should work fine. My video server just uses regular 320GB X 7 PATA drives for about 2TB, no RAID. Four channels from the MB and 4 from a PCI controller. But I don't mind if I lose a drive as it's all from files that I have the originals of. Access is over a gigabit LAN in a back room to my HTPC in the front room.

Performance of the drives or controller may not be a problem. The bottleneck for me has always been the LAN, not the drives or the controller. And not for playback, but transfers to the server. Playback worked fine even over a 100MB LAN. The gigabit helped, but still needs some tuning to improve the transfer speeds.

Since I'm running out of space on the server, I plan to put together a second server with SATA drives, probably 320GB drives again as they seem to be the best setup for cost and reliability.

I just wish SATA controllers were cheaper.

[mike909]

Yep, I will have a similiar setup (Gb lan). When you say bottleneck for transfers to the server, has it ever been so bad that recording via htcp to the server dropped frames? I plan to use the array as the 'recording' volume from htpc to file server. I'm really flip-flopping now, on whether to go with the dedicated adaptec controller (300$) or just use the onboard raid 5 controller (72$ for mobo). Huge price difference there, especially considering the fact I need to buy the mobo regardless.
I think windows (vista mce is what I will be using) has to be fine-tuned for a gigabit connection (naslite, which will be file-server) is linux so I'm hoping that won't need any optimizing.

[redwudz]

I record to the HTPC, then just transfer the edited video to the server. Never had any data loss, even with traffic on the LAN and running the internet through it. Just takes longer than I would like to transfer large files. In fact it's not noticeably faster than the 100MB LAN it replaced.

I did make some changes and enable jumbo frames and adjusted some buffer settings, but I haven't ran a transfer speed test since then. But I'm not that knowledgeable about networking.

For your setup one other slight worry might be if the SATA PCI-E card driver and the on-board SATA driver will have any conflicts. But the card's manufacturer may have any compatibility problems listed on their site.

I would be tempted to try the motherboard SATA 5 setup first, then look into a controller board if needed.

[jagabo]

Unless you're talking about streaming multiple high bitrate streams simultaneously hard drive speed isn't an issue. Remember typical hard drive speeds run from about 20 to 80 MB/s, a DVD MPEG2 file about 1MB/s. And 100 Mb/s ethernet has only about 10 MB/s throughput.

[mike909]

I record to the HTPC, then just transfer the edited video to the server

I have a small OS drive in the HTPC and that's it...hope recording directly to the server doesn't give me any problems.

I would be tempted to try the motherboard SATA 5 setup first

Yes, I believe I will try the onboard first, and go from there.

In fact it's not noticeably faster than the 100MB LAN it replaced.

that kind of sucks.

And 100 Mb/s ethernet has only about 10 MB/s throughput

Rite, which is why I was hoping the 1gig would provide a lot more throughput to the server, as the gig is somewhere around 100MB/s throughput? I wasn't sure if I would need sata-II drives, or if I should stick with my SATA-I drives, looks like the sata-II wouldn't provide me any advantage, as the bottleneck will be the 1gig LAN.

[jagabo]

The SATA I interface has a theoretical throughput of about 150 MB/s. SATA II about 300 MB/s. The rate at which you can read data of the platters of a single drive is currently in the 40 to 80 MB/s range. The interface speed won't be an issue unless you use RAID.

A single SATA drive will have no trouble serving several DVD MPEG2 streams over 100 Mb/s ethernet. You'll likely run into seek time issues before you run into ethernet throughput bottlenecks. Where you'll start noticing the ethernet bottleneck is when copying files from one computer to another.

[redwudz]

I did go ahead and benchmark my gigabit LAN connection to the server. It shows 54MB/s or about 432Mb/s which is very good. I was in error saying it wasn't much faster than my 100MB LAN. It just seems slow when transferring 10 - 20GB files. A free benchmarking program, Sandra XISP2 Lite: http://www.sisoftware.co.uk/

54MB/s is about the limit for a PCI or on board LAN card. The hard drives don't seem to be too big a factor with my setup. They are 320GB 7200RPM PATA drives. I did time a file transfer of 700MB and that happened in about 13 seconds, so that seems in line with the 54 MB/s benchmark.

At work I have a 100MB/s LAN connection to a computer about 100ft away and it benchmarks at about 1MB/s. That's about at 10MB/s LAN speed, so there is a problem with that setup.

But to get back on topic, RAID 5 should suit your purposes, mainly for prevention of data loss. I'm setting up a second video server with eight 320GB SATA drives and two SATA controller cards, no RAID. Since the MB is a little older, I'm just using PCI controller cards. It will also be hooked into the gigabit LAN and use the on board 100MB NIC card just for wake-on-LAN. That allows me to turn the servers off and on from the HTPC.

[mike909]

Thanks for the test results redwudz. Good to know. It appears either of our setups should be more than sufficient to record to and read from dvd quality mpeg2.

[rallynavvie]

I've been doing something very similar for a couple years now but on a bit larger scale. I have a 24-bay SATA storage array acting as my file server (driven by my more-than-capable Tyan 2460 currently) with three Adaptec 2820 SATA controllers to drive those bays. I've been adding SATA drives to the array as I need them but it started with 8x 250GB drives. It's running Windows Server 2k3 and basically sharing drive space as specified. I needed to run a Windows OS as there are other applications being driven on this rig as well (the OS/apps are on an Adaptec 39320 with two mirrored 74GB 10k U320 Cheetahs).

I've been using a dual GbE NIC on the machine for data transfer. I'm essentially duplexing my GbE connection for easier throughput with the server. The onboard NIC is now the console connection. I use a simple Netgear 24-port GbE switch for wiring the place. From 100-base I've found about 6x the performance with copper gigabit connection.

With my current HTPC setup I can record analog TV from two channels simultaneously to the server while watching recorded video from the server. I've even been able to record an HD channel and an analog channel while watching an HD feed. The only time I've had hiccups is when I'm pushing things by copying files (as in hundreds of GB in size) one way or the other while trying to record/playback media from the server. Save the solid file transfers for times when the system is idle. Otherwise everything has been working wonderfully.

[RabidDog]

One point to mention tho ..is that the raid you create with the on-board controller will NOT be compatible with the Add-in card , thus needing a lot of jiggery pokery to transfer your files and de-raid and re-raid.

[mike909]

the raid you create with the on-board controller will NOT be compatible with the Add-in card , thus needing a lot of jiggery pokery to transfer your files and de-raid and re-raid.

That brings up an interesting point. A raid-5 is great for it's redundancy (safety), but what happens when the controller dies? The controller is not redundant in any way, so lets say the controlle dies 3 years down the road, and I can't find that same exact controller again for sale? I would hope that since raid is a standard, there would be some way of getting that array back, just not sure how.

[TBoneit]

Hopefully the Adaptec card will be a lot more reliable than the Motherboard. Whci brings up the other benefit of a raid card. It is transferable to another Motherboard with the raid still intact and working.

Some of the less expensive (Sil ) raid card seem to break teh raid if started with one drive disconnected even.

However if the card dies and you can't get the same one you could lose your data. The Adaptec should be durable though.

[mike909]

if the card dies and you can't get the same one you could lose your data. The Adaptec should be durable though.

Well, it will die. Rest assured, hardware fails (not often, but it does happen). I'm sure there is a way to rescue an array w/ a dif. controller, just no idea how difficult that may be.

[mike909]

I've been using a dual GbE NIC on the machine for data transfer. I'm essentially duplexing my GbE connection for easier throughput with the server.

Sounds like a good setup you have there, the windows lan connection "bridging" actually works? For some reason I thought that would cause more problems than it was worth. Good to know.

[rallynavvie]

I've used the bridging feature before to do a adhoc LAN via FireWire to a laptop since I had run clean out of network drops at that location. However since each NIC still grabs an IP I did something with the switch to define one upstream and one downstream port. It wasn't working for a while, like sometimes internet latency would be terrible or I couldn't see a printer on my network, but I messed with it some more until that went away entirely. Wish I knew what I did though

[redwudz]

rallynavvie, I was going to ask how you set it up, but I know the part about not being sure how you got it all working properly. I've ran into that a few times with networking. I haven't thought about 'bridging'. I probably don't need any more network complications and my system is fine for video viewing. But it would be nice to speed up transfers a little. 8) Hmm... Bridging....... More to learn and more mistakes to make.

But I don't want to mess it up (Again ) since it works fine at present. I had one drive on the server that was not accessible from one computer for writing, so I moved the NIC over to the gigabit switch and I had to redo the network settings of every computer. I just have a 8 port switch, and 1 port is used for the router input. I guess I could pick up another switch and a few more gigabit NICs. 8)

Something more to play with. But not until I get my second server up and running in a week or so. But still no RAID.