System specs & Components
Lenovo ThinkCentre M720 Tiny Thinclient
Windows 10 Pro
i7 8700T, 6C/12T @ 3.8 boost 1.7 base
16GB DDR4 SODIMM
500GB WD NVMe SSD
MSI GTX 1650 Super 4GB DDR6
2x PCIe 16x to 16x extension - I recommend these over the regular gray ribbons, I had issues with those and had to replace one - Link
1x PCIe 4x to 16x extension adapter (external power, which is important) - Link
Lenovo 01AJ929 PCIe 4x adapter - Note: this was not in stock at this link and I waited two months to find that out. I ended up having to order from ebay UK and have it sent to shipping forwarder to get my part to the US - Encompass Link
265W 1U server power supply - Swapped two 40mm fans with Noctua Silent Series
*** I used links for the pictures to not clog up the thread with high res images.
*** For reference, the two RivaTuner FPS screenshots during benchmarking were before and after I resolved the CPU power throttling issue. As you can see, performance was night and day.
Valley Benchmark Score: 4435
Min FPS: 37.1
Max FPS: 194.7
I was able to finally run some benchmarks and get this overclock a little more dialed in. I noticed FPS was not as it should be (I had seen 90 or so in game and it was dropping below 50) so I played with the overclocking settings on the GPU a bit and found a much nicer sweet spot. The memory overclock when I was having issues was only 100Mhz over, but I think it didn't like it and was throwing memory errors causing me to drop frames. After I got the GPU settings good, just for fun I went and ran the same benchmarks with the CPU fan on full blast via the bios setting. There is no way I would run my system like this, it sounded like a jet and I don't think the fan would last long that way either. It did get me 1.5 more FPS on average, which is negligible, and brought testing temps on the CPU down to 56C from 70C.
Novabench Overall: 2593
I am getting varying scores on the CPU when running Novabench tests, and I noticed it is showing a different clock speed during each test run. I suspect this is either thermal or power related, I was originally thinking power, however digging on the Throttlestop forums I may be able to unlock a little more performance from there too. No time to play with that now but some tweaking will definitely be in order. The best overall Novabench screenshot is here and that test was done with the CPU fan on full blast to pull a little more out of my CPU score. The GPU scored a slightly higher 898 before I cranked the CPU fan. Info on pushing the CPU a bit more with ThrottleStop settings is at the link below.
Installation Steps & Comments
This build took some time to plan and put together, but it is finally working and working well I am happy to report. I found that this machine has an internal PCIe 4x slot that is a proprietary Lenovo conenctor, but with an adapter (from Lenovo) you can get a regular 4x slot out of it. Adapter part number is above with link (check stock by calling first!). After having some issues with the grey ribbon style PCIe extenders, I bought some nicer looking black ones that had more rigid connections at the PCIe boards and so far so good with those. The whole thing is mounted on the back spine of my desk and besides the wires you cannot tell there is a whole computer attached to the back of it. I am using the GPU power supply to also power a USB hub and RGB lights also mounted to the desk, both on 12v. I am using a 5v opto-isolated mini relay to turn on the PSU by shorting the POWERON pin to GND. The relay is triggered by 5v coming from the USB port on the PC.
Once I finally got it running and playing games, I found performance was decent but not as good as I expected. I was getting 25-40FPS in game when I was expecting 60 or so (Ghost Recon Breakpoint, most settings high 1080p). First I went to HWInfo, and found that some throttling was going on. For a few moments at a time, my CPU was at 950 Mhz when it should have been 3.4-3.6. Initially I thought this was thermal throttling going on maybe due to limits set in the BIOS since this was such a tiny machine, but I was not seeing more than 50-55C on the GPU or CPU, and the CPU was only using 5-10W of its 35 TDP.
I then installed ThrottleStop, since I was familiar with that from the laptop world, to see if I could force it to do what I wanted it to do. When in game or in benchmarks I was getting constant BD PROCHOT alerts and I noticed it was throttling when throwing that. Okay, quick google search says that means SOME external signal or the CPU itself is telling the CPU to throttle. Again, I thought thermal issues, but looking in HWInfo again, it seemed like the only throttling the GPU was doing was due to power, not temp. I tried disabling BD PROCHOT in ThrottleStop, and that resulted in a few instant shutdowns (when already warm or at a high load) and random reboots when in game.
At this point I was using an UNPOWERED 4x to 16x adapter, so all the PCIe slot power was coming from the motherboard. Since I knew this was power related, my thought was either this PSU is on its way out and can't keep up with the load, OR it was pulling too much out of the motherboard slot. The power brick for this little machine is not more than 100w, so I was leaning that direction, however I was seeing 12.1v coming from the motherboard PCIe slot and 11.5 coming from the PSU for the 6 pin power, so this lead me to believe I had a voltage drop in the PSU. Swapped to the POWERED 4x to 16x adapter, hooked it up to the Molex connector from the PSU, and buttoned it up. This fixed all my issues. In ThrottleStop I turned off BD PROCHOT again, but this time I did not have any reboots or shutdowns, and I am now seeing my CPU pull the full 35w that is available to it and it is no longer throttling due to PD PROCHOT or temp.
My conclusion as to what was going on is that my GPU was hitting the power limit of the PCIe slot (by way of the motherboard and it negotiating wattage available there), so that caused it to throttle itself. When the GPU or other components throttle, they can send the BD PROCHOT signal to the CPU to tell it to throttle, essentially a "safe limp mode" like your car does with a check engine light. Disabling BD PROCHOT without the necessary current available at the slot resulted in those instant shutdowns. I had one that may have been thermal related, but I have a feeling the rest were caused by not enough wattage available for the whole system (I was pulling too much out of the slot) and it shutdown on a voltage drop. Once I got enough power to the GPU PCIe pins, it was still throwing BD PROCHOT since the wattage at the PCIe slot was still negotiated at the same current (25w I think) but of course there was much more wattage available since it was coming from a separate source. Trick it to not throw BD PROCHOT with ThrottleStop, and all is well now. Another observation I made is that voltage difference between PCIe slot and 6 pin power before swapped adapters. That could wreak havoc on all sorts of current readings and other reference values, so that could have been a problem in and of itself. Once I got the powered adapter hooked up, of course slot and 6 pin 12v line was pretty much equal, which is what it is supposed to be.
In game I am running around 70-75C on the CPU, the only thing I can do about that is look for software to adjust my fan curve. The next setting up in the BIOS for fan speed is "full speed" and the noise is unbearable. I can deal with 50-70% fan, not 100% all the time. With the location its in, I could technically just remove the cover and swap it for a proper tower cooler, but I would like to be able to keep it a little more "stock" looking if possible, besides the hole I cut in the lid for the PCIe extender of course...
Before I fixed the throttling issue, my benchmarks were about equal with what I was seeing in game, 30-40 FPS during 3D GPU tests. Once I got that taken care of, the same benchmark showed around 95 FPS, so I am certainly happy now.
@merritt_bishop, This is very cool! Thank you for sharing the build and links to those adapters.
@itsage, thank you, I am running CPU benchmarks as we speak and this little thing has been chugging away for 10 min with all 12 threads at 100%. Fan is spinning at 50% which is definitely doable for gaming, and the package seems to have maxed out at 74C with each core just barely touching 75 here and there. I suspect this is the TDP limit at this point, because I am still getting a "POWER" limiter showing in ThrottleStop.
Another cool thing, I found out last night this little beast can take an i9 9900T, and it is only valued at $50 more than my current CPU based on ebay rates. That gets me 4.4 Ghz and 8C/16T, so I think I will be trying that out very soon. Just need an extra $280 to put out there and time to wait on China shipping lol
Thank you for your build. Two things:
1. Mind formatting in the build template format for easy readability?
2. Can you do a CUDA-Z or AIDA64 bandwidth test to confirm stability and bandwidth? Private testing with that PCIe extender you are using found it's woeful at anything other than Gen1 link speed when tested on a laptop m2 port.
@nando4, no problem, will make the edit shortly. Playing with overclocking at the moment so I would be happy to run a bench. Just played Steep on Ultra and Ghost Recon Breakpoint on all high and it held 50+ FPS the whole time with vsync limiting me to 60 since my screen isn't the best.
@nando4, just made the edits, and a brief update. Performance is amazing, both for the PC itself and the relatively mid ranged GPU I chose due to budget constraints. I had used a variety of these ribbon style adapters in the past on custom server builds (mainly to fit full height cards in 2U low profile cases) and have not had many issues with them. This time around with all the bending and flexing I was doing, I must have broken one or two of the extenders. I isolated it to one testing in my son's PC, but then when putting mine back together I would either get no video at all or it would boot into Windows but run extremely slow and only show the Intel Integrated GPU even though the monitors were plugged into the Nvidia. The black extenders I ended up with are a much better build quality, instead of the ribbons soldered to the board and no physical reinforcement, these actually have a slit of board material riveted on top of the ribbon cables to hold them in place and not pull on the solder joints. Hooked the new ones up and then had to troubleshoot the card throttling due to PCIe slot power that I described above, but otherwise this thing has been great ever since.
I did play with overclocking a bit, and it seems to run well with a core clock of around 2115 Mhz, but I really was not able to push memory too far. It runs reliably stable up to around 6300 Mhz before crashing (I did get up to 7000 Mhz but some games would crash randomly) but I found that I am loosing FPS with anything more than 6100 Mhz or so, likely due to VRAM errors.
Overall, the system is extremely stable. Thermally with the CPU pinned in game, 70C is pretty much what it likes to sit at with the ambient temp in my room. The GPU on the other hand, since there is no case to hold in the heat, idles at a cool 28C and I've not seen more than 55-60C in game with an average of around 50C. The GPU temps really make me want a more powerful card I can push a little more from a thermal standpoint, but the GPU market is insane right now so for the moment I will take what I can get. A 1080Ti or something would be great in my book, but would also be at the limit of this little PSU (250w card on a 265w PSU isnt enough headroom for me), so I would need to make an upgrade there as well.
Happy you guys liked it. I was lucky enough to grab this Tiny for free doing computer recycling so this was very much a budget build, and I prefer to do things a little "different" usually anyway so this was right up my alley. I have a feeling the i9 and a 1080 is in my future soon 😎
Edit: I did notice the CPU has gotten up to a max of 81C while gaming, but the GPU is quite cool sitting around 45C at 100% usage and 85% VRAM. Makes sense since it doesn't have a case. I just set MSI Afterburner to start on boot with the overclock on, but ThrottleStop defaults to BD PROCHOT being enabled, so it limits the GPU down to its base clock and about 10w worth of power on the CPU. I will do my everyday computing with it enabled and then just bring up the application and uncheck the box when I need it for gaming. Works very well.
In Breakpoint I was getting 60-70 FPS with most settings on high (I think Terrain on Medium and all else high) and with BD PROCHOT enabled, it dropped to 10-15 and looked horrible lol
@merritt_bishop, can you put up some detailed photos please of your installation, I am interested as to how tidy this could look and permanent setup
@james_green, I'm in the middle of some home renovations now so I'll be pulling the desk out and it's due for a good dusting anyway. I have pictures linked in the OP (I stuck them in Google Photos to not clog up the thread) but I can take some of the final setup in the coming weeks when it's out for cleaning.