Old comps

John
John
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Topic 211754

Hi guys,

what would be a decent config, in case you stumble upon some old comps, considering performance and price?

What about this one:

Intel i3 gen 3 or 4 /// 4gb ram /// Radeon RX 460 (video would be new, obvioulsy)?

Or better i5 or even i7 gen 3 or 4 (considering it is old and not very expensive anyway)? I know i7s have 4/8 instead of 2/2 or 2/4 but still, not sure it's a big difference, worth the extra cash.

Thanks!

 

 

Richie
Richie
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A few thoughts. If you would

A few thoughts. If you would like to run mainly GPU tasks then it wouldn't matter which CPU there was.

If you're interested in running CPU tasks then I would skip at least i3 and look for anything from i5/i7 gen2 onwards (i7-2600K). Because of the hyperthreading you would basically have much more freedom with i7. But each of those new generations recent years has given only about 10% addition in computing power when similar CPU models were compared. This is good to keep in mind when looking at prices.

If you know how to overclock computer and choose an "unlocked" processor this would compensate differences between those CPU generations and different models. Also if you plan to max out CPU resources by running plenty of CPU tasks then a decent CPU cooler would be recommended (especially if overclocked).

Sometimes 4GB RAM could be a bottleneck as there have been apps that require more than 1GB per task.

I'm not saying it wouldn't be interesting to crunch with any i3. It always is. It's just desicions: what do you want to see happening while crunching and what value an X amount of money has for you (different models, different prices).

mikey
mikey
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Richie_9 wrote:A few

Richie_9 wrote:

A few thoughts. If you would like to run mainly GPU tasks then it wouldn't matter which CPU there was.

If you're interested in running CPU tasks then I would skip at least i3 and look for anything from i5/i7 gen2 onwards (i7-2600K). Because of the hyperthreading you would basically have much more freedom with i7. But each of those new generations recent years has given only about 10% addition in computing power when similar CPU models were compared. This is good to keep in mind when looking at prices.

If you know how to overclock computer and choose an "unlocked" processor this would compensate differences between those CPU generations and different models. Also if you plan to max out CPU resources by running plenty of CPU tasks then a decent CPU cooler would be recommended (especially if overclocked).

Sometimes 4GB RAM could be a bottleneck as there have been apps that require more than 1GB per task.

I'm not saying it wouldn't be interesting to crunch with any i3. It always is. It's just desicions: what do you want to see happening while crunching and what value an X amount of money has for you (different models, different prices).

I totally agree with what Richie says!! In fact I have an OLD dual core running a gpu here but not running any cpu workunits because the it can only handle 4gb of ram, the gpu is doing fine, it's an Nvidia 760, and the pc is running Linux. It was easy to get it up and running under Linux on the Nvidia gpu, AMD's I haven't found the trick too yet despite several how to's being posted, and I turned off the updating of the pc so it just crunches. I do do updates about once a month or so, but other than that it just runs.

Gary Roberts
Gary Roberts
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John_147 wrote:what would be

John_147 wrote:
what would be a decent config, in case you stumble upon some old comps, considering performance and price?

As others have mentioned, unless you want to crunch CPU tasks only, the CPU is relatively unimportant for GPU crunching.  I take it that the example that you used

Quote:
Intel i3 gen 3 or 4 /// 4gb ram /// Radeon RX 460 (video would be new, obvioulsy)?

indicates that you are interested in GPU crunching?  If so, the following comments about giving new life to old hardware might be of use to you, since they are specifically aimed at upgrading with a productive GPU.

Before the advent of GPU crunching (around 2009), I built a number of hosts specifically for CPU crunching.  The CPUs involved were both dual and quad core, Q6600, Q8400, E6300 from Intel and a couple of Phenom II from AMD mainly for comparison purposes.  Intel tended to be more expensive to buy but much cheaper to run with significantly better output so I've tended to use Intel exclusively since then.  With the advent of Ryzen, that could easily change in future.

I still own all those old machines and around 2015 I was thinking about retiring them.  I had the opportunity to buy AMD HD7850 GPUs (Pitcairn series) at the time quite cheaply (basically the same GPU existed in the new R9 270 and old stock was being cleared).  I tried a couple and found how well they would perform in the hosts I was going to retire so I bought a bunch and upgraded instead :-).   They are all still running. I haven't had a single HD7850 failure in that time.

More recently (early this year) I brought some Q6600 based machines out of retirement (they were 2008 vintage) and upgraded them with RX 460 GPUs.  They produce pretty much the same as a HD7850 using quite a bit less power.  The ones I have don't need an external PCIe power connector.  As a result of this, I've bought more RX 460s and upgraded other 'close to retirement' hosts that had Q8400 and E6300 CPUs.  These do quite well power consumption wise because I only use 1 core for crunching CPU tasks.  They consume around ~160W at the wall crunching 2xGPU and 1xCPU tasks.  RAC (pretty much independent of CPU) is around 250-300K.  They run on 300W PSUs (rating is 270W on the 12V rail)

There are a couple of things that are very important to consider if you want to go the upgrade route.

  1. Don't use the existing PSU in an older machine if it's not a modern design.  Avoid generic PSUs that are 3.3V and 5V 'heavy'.  You need a PSU that can supply pretty much its full rated power on the 12V rail.  Inspect older PSUs internally for swollen capacitors and non free spinning fans.  A 300W PSU should be OK for a RX 460 (or RX 560) GPU provided it can deliver at least 270W @ 12V.
  2. If you need to upgrade the PSU, don't just accept the ratings as written on the label and don't buy some no-name cheapie.  Find the UL code on the label ('E' followed by six digits usually fine print and located near or under a rather large backwards 'R' merged with a 'U' to form a sort of sloping logo).  Google the code to find out who actually made the PSU.  Google the PSU model to find any reviews.  Don't buy a PSU that's not at least 80+ certified - perhaps at least 80+ gold.  If you plan to run the machine for more than a year or so, it's worth the extra.
  3. You don't need a whole heap of RAM and faster RAM doesn't seem to make much difference.  I try to have 4GB in my older hosts - dual channel does seem to matter so 2x2GB rather than 1x4GB.  I have several running very well with 3GB (2GB + 1GB) without any noticeable ill effects (still reports in the BIOS as dual channel.  I even have a couple with 2x1GB that are still able to run 2xGPU and 1xCPU tasks without hitting the swap space whilst still running a full KDE desktop environment.  I'll get around to finding some more 2GB sticks one of these days :-).
  4. Pay attention to case cooling.  Rather than adding/upgrading case fans, leave the sides off if possible.  That does a better job than case fans.  Also much easier to regularly inspect heat sink fins for buildup of dust and fluff.  Using a soft brush and/or compressed air, remove any accumulated debris.
  5. Pay attention to motherboard capacitors.  Don't try to use any older machine that has obviously swollen capacitors on the motherboard.  It likely wont run under load for very long.  Motherboard capacitors are replaceable if you have a decent soldering iron and basic soldering skills.  You just need to find low ESR (preferably Japanese) caps with equivalent (or higher) voltage rating and about the same micro-farad rating.  Good brands are Panasonic, Rubycon, Nichicon, United Chemicon, for example.
  6. When considering the purchase of an older machine, don't pay a premium for i7 or i5 and don't buy AMD.  I have tried an FX-6300 hex core and (even ignoring the extra power) it can't get the same output with the same GPU as a Pentium dual core or an i3.  And the power draw is higher too.

 

Sorry this has become so long.  Hopefully some of it might be of some use to you - or to any others who might be interested in exploring the same path.  I think GPU upgrades like this are a good way to increase output relatively cheaply.  Make sure it's a relatively modern GPU - RX 460/560 [not 550] can be found quite cheaply and perform really well.  I don't use nvidia - too expensive in my neck of the woods and older ones that are more affordable (like the 750Ti for example) produce less than half of what I can get from an RX 460 (RAC of 115K compared to 270K).

 

Cheers,
Gary.

John
John
Joined: 1 Nov 13
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Thank you guys, many useful

Thank you guys, many useful things to know.

Regarding the CPU/GPU topic, mixed with a certain budget, I choose now GPU tasks. The configs I was asking about were designed for GPU work. I think CPU tasks are better run on servers, not "home-built" comps. Even if the latest gen of Intel processors has 6 cores and 12 threads, it's still low compared to a nice Xeon proc.

Cheers!

 

mikey
mikey
Joined: 22 Jan 05
Posts: 3901
Credit: 364878097
RAC: 182125

John_147 wrote:Thank you

John_147 wrote:

Thank you guys, many useful things to know.

Regarding the CPU/GPU topic, mixed with a certain budget, I choose now GPU tasks. The configs I was asking about were designed for GPU work. I think CPU tasks are better run on servers, not "home-built" comps. Even if the latest gen of Intel processors has 6 cores and 12 threads, it's still low compared to a nice Xeon proc.

Cheers! 

I have some of both of the cpu types you mentioned and the newer Intel ones are still faster, so while it is true that most cpu projects have a while to run yet the newer cpu's do get thru the workunits faster than the older Xeon cpu's. My Xeon's are quad cores with 2 of them in each box and they are each hyperthreaded so I have 16 cpu cores available. I did put a 750Ti gpu in each box too though, the power supplies are HUGE in mine and the combination just bangs out workunits at 2.6ghz. I buy mine on Ebay for around $150 US each with no hard drive and sometimes no gpu in them, but I have plenty of both and Linux is free and easy to make work on them. It's part of what let's me either focus my crunching to reach a goal quicker or spread them out so each project gets a little bit.

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