i'm trying to specifiy industrial computers for a process assembly line

in addition to reliability, the most important thing is "system availability" .. that we can get identical (or at least compatable) replacements for (hopefully) up to 10 years.

so my questions:

HDD's .... which has better expected reliablility and expected availability... SATA or IDE?

RAM. should we go DDR2, or is DDR expected to be around for a long time? also, what about ECC... is it really that much more reliable compared to non-ECC Grade-A RAM? we aren't worried about speed, just stability. does anyone expect ECC to fully replace non-ECC within the next 10 years or so?

answers greatly appreciated, as are any links to tech resources describing this.

2/1/2008 11:48:54 AM

DDR2 and SATA. SATA will be around in revisions for at least another 10 years and by spec is fully back and forwards compatible (just with speed penalties/enhancements)

DDR2 will probably only be around for 3-5 years, but DDR is now getting pretty scarce in terms of production, making it almost unusable for a timeframe like that.

2/1/2008 12:00:56 PM

Quote :

"what about ECC... is it really that much more reliable compared to non-ECC Grade-A RAM? "

Yes, Va. Tech replaced their entire cluster JUST to get ECC. From what I read, they hard horrible crashes during any sunspots because of random failures that were induced. Definitely go with ECC if uptime is a priority.

Quote :

"does anyone expect ECC to fully replace non-ECC within the next 10 years or so?"

I doubt it. It's a tad slower for some things, which means consumers (gamers) are going to stick with their mostly good regular ram for a while, i would predict.

DDR also will probably be around, but very expensive in 10 years. Even DDR2 would be pretty expensive. I'd go with DDR2 though because it's cheaper now and at the start of its lifecycle, unlike DDR.

2/1/2008 12:01:28 PM

so do you want to build these industrial computers out of commodity PC hardware? If so, look at PC hardware from 10 years ago. You can't go to a vendor like CDW and buy replacements but you can find hardware if you NEED it through the used market.

Can you not use network storage instead of HDDs in the computers? That would be easier to maintain long-term. I would be looking into how you can separate the specific PC components from the industrial process

Flash-based storage will be more reliable than sata or IDE hard disks.

Grade-A ECC RAM is more reliable compared to Grade-A non-ECC RAM. If you buy a good server, it will alert you when an ECC RAM stick has an error (just had this happen recently), so you can schedule to replace it.

2/1/2008 12:02:14 PM

Quote :

"If so, look at PC hardware from 10 years ago. You can't go to a vendor like CDW and buy replacements but you can find hardware if you NEED it through the used market."

i doubt they want to use used hardware in a production environment...where uptime is crucially important. who wants to use outdated hardware anyway?

2/1/2008 12:15:04 PM

^ well, the original poster said he wanted to buy replacements in 10 years.

2/1/2008 12:23:32 PM

10 years is probably a bit too optimistic.

but if we're dealing with, say, 5-yr old machines, and one goes down.... we'd probably do whatever was needed to fix it. the key is not so much age of the component, but if it is completely compatible or has replacement parts available.

the last thing you want to do in a uniform production environment is to get a totally different machine then have to rebuild the custom software, get new drivers, or buy different instrumentation cards altogether.

2/1/2008 12:54:26 PM

thanks for your help everyone.

agreed: im going with SATA and DDR2... and ECC is not important for this application

2/1/2008 1:42:19 PM

one more question

P4 or Core2Duo?

how long is the P4 expected to remain available?

2/1/2008 2:00:11 PM

p4 is dead

core2 is your only real route, even then it wont last 5 years as an upgrade path.

2/1/2008 2:27:00 PM

thanks for the help

ive decided on Core2Duo 2.0/1G DDR2/80G SATA

its pretty much the only sensible choice.



now...anyone want to beat $1200/unit for 2U rack-mounted machines? need about 30 of them in a month

2/1/2008 8:29:29 PM

PM me specs and ill quote you on em, might be a fun side project for me since its been a few years since I had my builder/integrator hat on

2/1/2008 8:33:12 PM

why not thin client terminals or something like that

2/1/2008 11:52:13 PM

^ because we don't use a central server to control manufacturing processes, and we use GPIB cards in each machine to run a host of calibrated test equipment to perform electrical tests on the devices. ... so we need dedicated machines in a 2U rack mounted chassis at each test station.

^^ specifically

2U chassis, not more than 19" deep, cabling access rear panel
industrial "long availability" motherboard
suitable powersupply and cooling system
core 2 duo processor
DDR2 1GB grade-A ram
80GB SATA HDD
slim DVD-RW/CD Rom
2 serial com ports
4+ USB ports
2+ PCI slots (via riser card as needed)
onboard video
gigabit ethernet
windows xp pro OEM

2 year service warranty
4+ year guaranteed system availability





[Edited on February 3, 2008 at 11:29 PM. Reason : ]

2/3/2008 11:25:46 PM

i feel like i'm in 2006

2/4/2008 2:32:17 AM

Yep Im out with the warrantee. Not that I havent built reliable machines in the past (I can honestly say, knock on wood, I've only had one RMA/failure request out of several hundred machines I've built and serviced)

but its too much liability for me. If you decide you can do the servicing yourselves and use the part warrantees (which are now all 3-5 years), I'd be glad to take a look at pricing it. 4 year part availability shouldnt be a problem at all.

2/4/2008 3:25:53 AM

Or whatever...looks like I can't read that this thread has gotten alot further than where I decided to reply at....

--------------------------------------------------------------------

At the plant, we use SAS hard drives (full or mini size depending on when it was purchased). Our IT folks tried at one point to purchase a SATA set for one of our file servers and after five or six months of exchanging a drive a month then they gave up and sent it back to HP.

I would go with ECC DDR2 since it is newer and therefore more likely to be found in the future. Also, if this is going to be a common test set (i.e. you plan on installing this computer in a bajillion places) then figure out some percentage and buy them now and stash them away - you will need them. Depending on the system we try to have 100% spare parts with imaged drives. That doesn't always happen though.

One thing that even this board should show you that is whatever you choose will be obsolete yesterday so its best to prepare upfront.

[Edited on February 4, 2008 at 5:33 AM. Reason : i n00bed allover myself]

2/4/2008 5:30:30 AM

I don't know much about this, but if you are worried about parts in the future, wouldn't it help to buy several extra systems for spares/parts?

2/4/2008 10:36:10 AM

Quote :

"during any sunspots "

damn the neutrinos!

2/4/2008 10:40:28 AM

I don't know the situation exactly, but this program screams virtualization to me. Why not keep all the machines you need for this as VM's so hardware really doesn't matter and you can just adopt the cheapest technology for a given product cycle?

2/4/2008 12:16:02 PM

Quote :

"i doubt they want to use used hardware in a production environment...where uptime is crucially important. who wants to use outdated hardware anyway?"

I know places that are still using VAX computers installed in the 70s for plant monitoring systems. They constantly have to bid on replacement parts on Ebay. Sometimes you're just stuck with outdated hardware.

*beeper goes off in meeting...* "oh crap, I just got outbid. I have to go!"

2/4/2008 3:27:53 PM

still curious as to why VM's aren't the clear solution, no matter what hardware you install vmware on

2/9/2008 5:32:27 PM

we're not just emulating desktop enviroments. it's 30 separate machines running hardware tests on production devices, interfacing a variety of physical equipment at each station.

add to the fact that it's Class III medical devices we're prodcucing, attempting to change to a network of centrally managed virtual machines would be a regulatory nightmare.

2/9/2008 6:56:43 PM

I was suggesting using vmware as a layer between your image and the hardware of the workstations you're building, that way homogeneous hardware that's going to be around from now til eternity wouldn't be an issue.

2/10/2008 11:06:31 AM

oh... interesting idea

2/10/2008 12:38:59 PM

Quote :

"DDR2 will probably only be around for 3-5 years, but DDR is now getting pretty scarce in terms of production, making it almost unusable for a timeframe like that."

What will replace DDR2?

2/10/2008 1:24:17 PM

ddr3 is already out... but 2 will be supported for longer than 3-5 years.



[Edited on February 10, 2008 at 7:22 PM. Reason : ]

2/10/2008 7:21:37 PM