View Full Version here: : Need a robust PC for the observatory?
29-06-2012, 12:41 AM
An expensive brand-name PC I have had in my obs has become unreliable lately - it's USB ports keep dropping out, refusing to connect, etc etc etc. So I have decided to replace it.
The key factors were:
1. reasonable but not necessarily blazing performance - a Core 2 Due at 3.0 GHZ will do;
2. Good build quality - not all computers are created alike - equates to reliability.
I already have a good old Dell desktop in the obs running one pier and it just keeps on keeping on so when I spotted Grays Online were auctioning some ex-lease Dell OptiPlex 755,760s the other day I decided to grab 2 of them and got then at $84 plus GST and freight each. An OEM version of Win7 Home Premium 32Bit for under $100 brought each PC in at under 300 apiece delivered.
As PCs go, these are drafthorses, not sprinters but they do seem to have a way of surviving where the others don't.
29-06-2012, 12:57 AM
Sounds like a good approach.
Personally, I steer away from brand name desktops. They're usually last year's (or older) components at inflated prices, at least when new, but sometimes worthwhile if second hand. I've favoured HP/Compaq in the past when I've gone that way.
For run-of-the-mill purposes, I buy commonly available used machines from eBay. i've bought plenty from eBay and have yet to have a problem. For high-end performance, I build my own with hand-selected components.
29-06-2012, 12:22 PM
For a robust setup I tend to go with servers when buying second hand, things like ECC memory and power supplies designed to be on 24/7 add up to a much, much more stable system.
For a cheap reliable new system, these are really hard to go past.
Less than $300, use ECC RAM, 7 USB ports and have 4 drive bays and are tiny and really reliable.
Not a speed demon when it comes to performance, but are still pretty quick, ultra reliable, tiny and use almost no power at all.
There are a few different flavours of the HP Microserver, some are a bit more grunty. They also make a great home media server, can playback 3D Bluray without a hassle, and again, lots of room for storage and don't add much to the power bill.
29-06-2012, 11:25 PM
It's more likely the USB problem is due to excessive cable lengths. 3meters works well, 5meters is dodgy. I'll bet both the DELL and HP boxes have ASUS motherboards anyway.
30-06-2012, 05:26 AM
Dell and HP tend to do their own R&D, haven't ever seen one with an ASUS board.
30-06-2012, 06:46 AM
Could it just be slight corrosion on the USB contacts?
What about a can of contact cleaner from Jaycar? There are two types - I've used the latter, but maybe the first one might be better for corrosion. Any comments from people who might know what they're talking about would be appreciated.
Option 1 (http://www.jaycar.com.au/productView.asp?ID=NS1434)
Option 2 (http://www.jaycar.com.au/productView.asp?ID=NA1012)
30-06-2012, 09:55 AM
Could be but I don't think so. The same cables and connections that the sexy big HP i7 dream machine won't operate, the old Dell operates just fine. This is the same HP PC that was in use when I fried my Gemini 1 control box - and whether it was a cause or not, so I just don't trust it.
30-06-2012, 04:54 PM
I would have recommended CRC Freon cleaner - if you could find it these days.
Last century this was the recommended electronic contact cleaner in aviation.
But most Flurocarbon variants were banned to protect the Ozone layer.
This CRC product would seem the next best alternative:
Note the MSDS health effect if inhaled.
Saturating a lint free swab could assit in removing deposits. But as CO2 propellant will cause rapid cooling, allow to dry before reconnection.
The 400g can sells for around A$25. Blackwoods stock it.
There may be a cheaper brand?
The second Jcar cleaner contains mineral oil so should not be used.
30-06-2012, 05:01 PM
Thanks for the info David - what does the mineral oil do?
03-07-2012, 09:38 AM
A few comments:
1. When buying PC components I always try and buy the best (quality / capability) motherboards and power supplies. There are like an astronomer's mount - all other gear goes on them and if they're flakey - then nothing else will work well.
2. The HP Proliant micro servers seem to be making quite a name for themselves, mostly as home media servers. They are cheaper, more functional and just as expandable as a high quality NAS. When purchased probably best to combine them with Windows Home Server 2011 (no idea what that platform is like for astronomy gear).
3. If your USB ports are dropping out continually it gets incredibly frustrating. One thing you might consider is placing a high speed, powered USB3 hub between all your gear and your PC (meaning you may have to add a USB3 card to your PC, and run power to the hub). http://www.netplus.com.au/product/CBUS3-4PHUB/4-Port-USB3-High-Speed-Hub or http://cgi.ebay.com.au/ws/eBayISAPI.dll?VISuperSize&item=330622277895 A high speed, powered hub should be plenty fast enough for most needs at 5 Gb / sec and being powered it would run all your gear. It also means you only have to run one quality USB3 cable from the PC to the hub. I'm not sure what length active USB3 extension cables run in, but the alternative would be find a CAT 6 network cable to USB3 converter, run CAT 6 cable to the converter, run short USB3 from the convert to the hub, then run USB3 from the hub to your gear. This seems a nifty and extensible solution - so long as you can cheaply source all the gear. I'd search online first to see if someone has done all this with success first - as high USB is notorious for not working well on longer cable runs. 50 metres is nothing to CAT 6, whilst beyond 2 metres can confuse the heck out of USB2 cabling to devices! Additional some USB2 devices (e/g/ Meade DSI cameras) need special USB2 cables that deliver extra power to the device, a regular USB2 cable won't reliably work, you need the extra thick, extra wired USB2 cable they supply and then plug that into an active 5m extension cable with powered hub if you need to connect beyond 2 metres.
Hope these ideas help!
03-07-2012, 11:32 PM
Thanks Matthew. Much good advice there.
04-07-2012, 12:21 AM
Well I decided to buy a HP Proliant Micro Server today (been considering it for a while) - but when I saw the link to the discounted price of $265 - too good to lose! So I added 2 * 4GB of ECC RAM and just a single 2TB Seagate drive to start with, but I will option it up (removing the 250GB drive) as I need it.
My choice OS will be Windows Home Server 2011 (althought 2012 is 'rumored' to become available practically now). My idea is to run this as both a NAS to save user files daily, system images monthly and act as a media server (using Tversity Pro) to stream movies and music to all PCs, XBoxes, smart bluray players / media servers and PS3's in our house.
Fingers crossed; my guess is Windows Home Server 2011 might even make a very stable platform for an Astro lab (but you'd need to add a PCI express to USB3 card in a mini height configuration and a powered USB3 hub) for this to work well!
Thanks Poita et al for the heads up - great timing!
05-07-2012, 01:05 PM
Interesting, I have 2 "servers" in my garage datacenter that have run 24/7 for 3 years without hiccup (except the 2 times I powered them down to my houses, and the 2 blackouts that drained my UPS). I run approx 8-10 virtual machines across them, and they are made out of off the shelf components nothing serverish about them. My total DC consumes about 5kw/h per day.
05-07-2012, 05:53 PM
Its funny, using the term "robust" for astro and then only mention PCs and servers is daft. From my experience PCs get full of dust, corrode (from dew) and inevitably become unreliable in a typical OBs (unless its in a seperate warm room etc). Theres nothing "robust" about a regular PC or server in what really is close to an industrial application. These (http://www.fit-pc.com/web/) are robust. Sealed, no fan.
05-07-2012, 06:52 PM
This one just may pass muster for robustness.
Heck, now that IS robust Bert! :lol:
More than you could say for your wallet after buying one though!:)
06-07-2012, 07:29 AM
I was using the term 'robust' in the sense that they are reliable and do not crash. From that perspective servers with ECC RAM and reliable clean power supplies and low heat output fit the bill nicely.
If you have environmental issues, then that is a different kind of robustness required.
I keep my server inside a box with filtration to keep dust out and dessicant to keep moisture under control. The microserver generates so little heat (and uses so little power) that airflow isn't much of an issue, so a filtered cabinet works fine and costs a lot less than an industrial spec PC.
If you can afford one of those industrial/military beasties then they are great, we used to use them on-site at lidell and other power stations when building and monitoring the precipitators, now that was a harsh environment and robustness took on a whole new meaning.
For those who prefer real COM ports:
12-07-2012, 09:26 PM
Lol via they have some great ideas but are always to late to release there products and when they do there obsoulte.
If you want com's try this on for size http://www.scorptec.com.au/computer/46611-ser5466a 8 DB9M's on pci express w00t your never going to run short but even a 2x port card for $25 is plenty.:thumbsup:
13-07-2012, 08:37 AM
If you want a current intel CPU and 4 onboard serial ports, and low power usage, these guys have fantastic reliable boards.
You can make some beautiful tiny, powerful systems with these. They have complete boards about the size of my hand!
Or you can go for a mini-itx board that supports the i7 chips etc. and is bristling with ports:
There are some circumstances where very low power consumption is paramount, such as in off-grid setups.
And I have yet to find any astronomy application that will tax even an Atom processor. Yes, they struggle a wee bit with things like high resolution video encoding, but how many people are doing that on their observatory control PC? It's not as if it's going to be used for hard core gaming, or anything like it. Are they? :)
Considering these quad-core systems are low wattage and can be configured with up to 12 COM ports, I reckon they are very useful wee beasties in an observatory setting.
16-07-2012, 12:28 AM
There is a good guide here to setting one up.
16-07-2012, 04:10 PM
These look interesting.
I need a stable workhorse for my observatory. Been using a laptop but its been a bit flaky lately.
What type of card would be needed to add serial port to this ? My weather monitor still requires serial. Not having seen one not sure if low profile PCI serial card is needed or not.
18-07-2012, 12:44 AM
love the word robust when HP are concerned had the original HP41 and HP 41 CV (man landed on the moon using a HP 41) currently have a HP 50G.Old fan of HP
vBulletin® v3.8.7, Copyright ©2000-2013, vBulletin Solutions, Inc.