Spare CPUs get new life in PCs for donation

Article By : Brian Dipert

This engineer details the build of two PCs that were donated to provide computer access for a shelter program.

I thought this month I’d take a break from the ongoing series of posts about building PCs for myself and instead tell you about the PCs I’ve built for others, which I’ve conceptually mentioned before. While I’m certainly no saint, I do enjoy helping others less fortunate (materialistically and monetarily, at least) than myself, as well as not hoarding possessions to excess. And I admittedly can’t ignore the fiscal benefits of charity donation-induced tax donations, either.

Speaking of which, let’s first take a look at the Intel-based system I’ve donated to Evergreen Christian Outreach’s Shelter Program, a PC whose processing “heart,” a Core i5-3570, resulted from my recent successful transplant of a Core i7-3770 into one of my “Hackintosh” HP systems. I found myself with a leftover CPU via that procedure, of course, but aside from a WD Blue 500GB 3.5” HDD and an AOC E2243FW 21.5” LED-backlit TN LCD (which became available for donation after my wife upgraded to a 23.8” successor) I had in “spares” inventory, it turns out I ended up needing to buy everything else necessary to build a PC around the CPU.

Since the processor is nearly a decade old, it was nearly impossible to find a brand-new motherboard for it, and the few I found were selling for ridiculous markup prices (for those not already aware, PC component prices always go through an interesting cycle: list price at first, then marked down to clear out inventory when they’re about to be replaced with successors, and eventually much more expensive as folks who own systems containing them look for replacements). Eventually, however, I came across an open-box ASUS P8H77-M/CSM microATX motherboard on eBay for $89 that was truly in open box condition:

The item is in excellent, new condition with no functional defects. The item may be missing original packaging and may have been used for testing or demo purposes. The item includes accessories found with the original product and may include a warranty. See the seller’s listing for full details and a description.

Many eBayers have an unfortunate “creative” alternative definition:

I used it for a while (or maybe longer than a while) and then got tired of it, so I stuck it back in the box and put it up for sale. Since I included the “open box” it’s not “used,” right, dude?

photo of the ASUS P8H77-M/CSM motherboardSource: ASUS

The CPU also needed a heatsink and fan; I found a brand-new Intel E97378-001 for sale on eBay for $4.30. Quick aside: the successor E97379 series switched from a copper core to a less thermally conductive aluminum core, presumably for cost reasons; my search for and selection of the less common E97378 precursor was intentional. Perhaps obviously, I mated the CPU and heatsink with another dab of Arctic Silver 5 thermal paste. For memory, I picked up two open-box 4 GByte DDR3-1600 (PC3-12800) SDRAM DIMMs on eBay for 8 GBytes of total capacity at only $24.99. The optical drive, a refurb ASUS DRW-24F1ST from Woot! set me back $12.99.

The enclosure I chose was an elementary but eminently-serviceable Rosewill SRM-01B-450 microATX case from Newegg, which I got on sale for $39.99 including a generic (not even bronze-rated) 450-W power supply (PSU). For $5.59 extra, I got a three-year warranty on the case-plus-PSU combo. I also picked up an inexpensive but quality microphone-inclusive Aukey webcam, a set of speakers, and keyboard-and-mouse combo from Logitech. And finally, for software, I went with a “surplus” copy of Windows 10 Home purchased on eBay, along with a download-and-install copy of open-source LibreOffice.

Here’s the side view of the result, with the panel off so you can see the guts inside after tidying up the wiring:

photo of the inside of a PC built around the Core i5-3570 CPU

Although the PSU was beefy enough that I could have also included a discrete graphics card, doing so would have probably required that I hook up at least one more ventilation fan to the side (80 mm) and/or front (80 or 120 mm) of the case. And anyway, this particular system was intended for general-purpose use, not heavy-duty gaming. So, I instead just leveraged the graphics core already included in the processor.

Here’s a view of the front of the system:

photo of the front of a PC built around the Core i5-3570 CPU

Detail-oriented viewers may have already discerned that there’s something odd about the front panel. The optical drive “eject” button built into the case didn’t line up with the button on the actual drive, so I just removed the former, leaving a hole. You can still activate the optical drive’s “eject” button by sticking an unfolded paperclip or something like that in the hole; the button behind it is to the right but still accessible.

And finally, here’s the top panel (everything works as intended) and the rear view (the open-box motherboard even came with the original matching I/O plate):

photo of the top of a PC built around the Core i5-3570 CPU

photo of the back of a PC built around the Core i5-3570 CPU

Next, let’s go over the AMD-based system I built and then donated. As previously mentioned, the CPU, a “Trinity” quad-core A8-5600K (which came with a heatsink and fan), and the motherboard, a microATX MSI A78M-E45, had both been in my possession for … gulp … more than six years. Better late than never, right?

photo of the AMD Trinity quad-core A8-5600K CPU packagingSource: Newegg

photo of the MSI A78M-E45 motherboardSource: MSI

Two more open-box 4 GByte DDR3-1600 (PC3-12800) SDRAM DIMMs on eBay ($29.99 total this time) took care of the system memory needs, while another factory-refurbished ASUS DRW-24F1ST optical drive from Woot!, combined with another 500 GByte WD Blue HDD from my “spares” closet, handled mass storage. Speaking of “spares,” I also donated another AOC 21.5” LCD monitor to the cause. I bought another Aukey webcam, along with a set of speakers and a keyboard-and-mouse combo, all from Logitech. And for software, I again turned to Microsoft’s Windows 10 Home as the operating system, along with a copy of LibreOffice.

Last but not least, what about the enclosure? I’d found a slightly different Rosewill case on sale for this build, the FBM-06 at $24.99. It didn’t come with a power supply, so I transplanted a 400-W one that had come with another Rosewill case I’d gotten on sale, the $39.99 (plus $6.99 for three-year warranty) BM-X2-400. Why didn’t I just go ahead and use the BM-X2-400? It doesn’t have a built-in optical drive bay; I figured that forcing the system recipient to rely on a USB-tethered external optical drive was too user-unfriendly.

Here’s what this system looks like from the side, with the panel removed:

photo of the inside of a PC based on an AMD quad-core A8-5600K

Once again, although the PSU was likely up to the task of additionally powering a discrete graphics card, I decided to just rely on the graphics core built into the processor.

Front views next (the case’s built-in optical drive eject button worked fine this time 😉 ):

photo of the front of a PC based on an AMD quad-core A8-5600K

Now the top:

photo of the top of a PC based on an AMD quad-core A8-5600K showing the buttons and ports

And finally the back:

photo of the back of a PC based on an AMD quad-core A8-5600K showing its ports

Enough on the specs and the pics; how do both systems run? Great, in a word; so much so that I admittedly had a brief pause before proceeding with my donation plans. The CPUs are quite similar; both quad-core, no HyperThreading, 3.4 GHz base/3.8 GHz turbo clock on the Intel processor and 3.6 GHz base/3.9 GHz turbo on the AMD. The Intel CPU is a bit more power-efficient than the AMD one (77W TDP vs 100W), reflective of its more advanced manufacturing process (22 nm vs 32 nm); how times have changed of late! And as previously mentioned, they both have integrated graphics.

The open-box memory I installed in both systems passed testing with flying colors, and the refurbished optical drives look and work like new. The enclosures are perhaps a bit flimsy but perfectly usable, particularly given the price I paid for them. The accessories aren’t exotic but fit the bill just fine. And while the systems boot and launch applications somewhat slowly, due to their reliance on rotating HDDs, that’s nothing that an SSD transplant wouldn’t fix.

Speaking of SSDs, what about that other motherboard (and memory, and…) that I told you 6+ years ago I’d just bought? That all went in the third for-giveaway system I recently built, this time tailored for gaming, and intended for a teenage family member. The setup (therefore the story) is a bit more elaborate in this case, so I’ll save it for next time. Until then, I look forward to your comments!

This article was originally published on EDN.

Brian Dipert is Editor-in-Chief of the Embedded Vision Alliance, and a Senior Analyst at BDTI and Editor-in-Chief of InsideDSP, the company’s online newsletter.

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