I have been tinkering around with the x300 for a few weeks to try and find optimal settings, and came up with the following:
[SPOILER="Tuned x300 Settings"]
CPU side
Unless it is hidden somewhere, the x300 bios seems to provide no way to offset the voltage of it's boost to make it more efficient.
For finer control of max power draw and temperatures, I used manual settings, turned SMT off and settled on a 4.4ghz clock @ 1.3v Vid (1.24v under load), which results in a "CPU package power" draw of 54 watts during Cinebench, with temps in the low 70C range. This consumes about 65mv less package power under load than the automatically assigned boost voltage at the same frequency, which is 1.306v under load, PP=62w. A savings of about 8 watts.
In sustained workloads it should be more efficient, and also faster since the stock boost settles @ around 4.2ghz. In light and medium (gaming) workloads, it should be about the same performance, but with less heat and power.
Gpu/Memory side
This was really an interesting challenge. It seemed to be about striking a balance between the GPU and memory controller.
I found that 2000mhz FCLK with good timings and the 2200mhz GPU @1.15v Soc was a good compromise. The Corsair bdie kit here could probably keep going, but vDimm is limited at 1.35v.
2000mhz CL17 is about as fast as the 2100mhz CL18 level, but more stable for the FCLK & GPU.
[/SPOILER]
Unfortunately, the memory gets really hot... and the memory heatsinks + holes I drilled in the side just aren't good enough.
Asrock DID include a second fan header on the x300 though, if it can be used...
[SPOILER="More modding required"]
I decided to completely revise the duct design to incorporate 2x 40mm fans for active memory cooling.
To simplify the design, instead of adding 8 new screw holes for the 40mms, I designed some "guides" they can be placed on and only need 2 screws.
This was my first foray into shortening a fan cable, and possibly the most sadistic and tedious thing I have done in pursuit of SFF. As you can probably tell, I did not have the right tools for this job and soldered them instead of crimping. It probably took more than an hour to get all these 14 tiny wires stripped and soldered.
The fans fit, but I did not have the correct screws to attach them. And the "guides" did not hold them like I hoped. So this turned into an experiment of whether marine grade adhesive sealant is any good for attaching fans.
Very messy on one side, but (mostly) clean on the other and can't see it. Some got on the fan cable, but just on inside.
Putting it together. The 40mms sit flush with the CPU fan on one side and chassis on other side (just enough room for fan cable). Clearance over the memory is 1mm.
The paint could be better, but the fitment it turned out well. The x300 outer case is starting to get a bit of metal fatigue from all the abuse.
To test the results I loaded up Testmem5 to hammer the entire memory bandwidth continuously.
With RAM fans off, I had to stop the test when it climbed over 60c.
With RAM fans 100%, it is stable at 40c, and this is the "worst case". It is about 30-35 during normal use. So the fan curve can be set nicely.
With the modding and tuning complete, this build is done.
Regarding the gtx1080 as an egpu - I forgot that I put some copper heatsinks on the memory with permanent arctic alumina adhesive. So the stock cooler can't go back on unfortunately.
[/SPOILER]
With the modding and tuning done, here is an updated performance comparison:
It is generally able to run 1080p acceptably with settings turned down.
I thought to run Cyberpunk as a joke, but then realized it actually runs pretty well.
[SPOILER="Cyberpunk???"]
Cyberpunk is surprisingly playable at 1080p Low. It is even playable on Ultra after enabling Super Resolution, which gives it a few more FPS.
Super Resolution downgrades the resolution of objects at long distances. It increases the rendering speed without losing much visual quality.
Cyberpunk Image quality comparisons:
1) 1080p Ultra Preset - 14fps
2) 1080p Ultra Preset with Super Resolution set to Ultra Quality. Objects at long distances have less detail but it is not that obvious. - 21fps
3) 1080p Low. Still looks acceptable. - 29fps
4) 1080p Low, Super Resolution "Ultra Quality", Motion Blur on "Low" - 38fps
The image is clearly deteriorated at this setting, but it's a fantastic preset.
There is not really a reason to need to drop to 720p.
[/SPOILER]
[MEDIA=youtube]SzyPCVFzh78[/MEDIA]
