Ever since I start building computers, I have been obsessed with small form factors. After several Mini-ITX builds, I went a step further in 2013 and experimented with a Thin Mini-ITX, 35W Haswell HTPC. That in part was an effort to update my father’s perception of personal computers. He has always been a traditional tower user. To him, a computer means a metal box that is roughly 450mm*400mm*200mm. I want to show him how small a computer can be and still provide respectable performance nowadays.

Building that computer was quite eventful, in part because the form factor itself is pushing boundaries in many ways and  inevitably trades off compatibility with size. It was fun. But when a component did not fit, it cost both time and money.

Earlier this year I found a good deal on a ThinkCentre M93p Tiny. It is also based on the Haswell platform, and has a similar form factor as the Thin Mini-ITX HTPC I built. In this post I will present a breakdown of both systems, and highlight the similarities and differences.


All Sorts of Compatibility Issues

Initial Cooler: Silverstone AR04 SST-AR04

My initial choice of CPU cooler is the Silverstone AR04 as Silverstone recommended. The 23mm tall cooler is designed to handle 65W CPUs  and results in a footprint that is too large for some Thin Mini-ITX motherboard, the ASUS Q87T/CSM included. AR04 can only be installed in one orientation due to interference with VRM. In that orientation it still blocks both USB2.0 headers on the motherboard. In the second photo you can see that I use a USB2.0 9-pin to USB3.0 19-pin adapter in order to use the front USB 2.0 ports.

Replacing AR04 with NT07-115X

NT07 is compatible with the motherboard, but is incompatible with the case due to the fact that its backplate is thicker than the height of motherboard standoffs on the PT13. I wrote about it in detail in my Amazon review of the cooler.

Replacing NT07-115X with akasa AK-CC7122BP01

The NT07-115X and AK-CC7122BP01 are nearly identical (even packaging, except that the Silverstone uses a backplate and the akasa uses a simpler push-pin locking mechanism. See here for a quick unboxing of this cooler. This cooler finally solves the compatibility issues on the cooling side.

Even with cooler issues all sorted out, this build is not yet 100%. A remaining compatibility issue is between the motherboard and the case. One of the three screws on the CPU socket and backplate is longer than, you guessed it, the height of the motherboard standoffs on the PT13. I am not sure who to blame on this one. If you look closely in the photos you can see that the front two motherboard screws are not used due to the motherboard being “lifted” by the protruding socket screw. Luckily the case lid can still be closed, and I was at least able to finish the build without a major sacrifice in functionalities.

Lenovo M93p Tiny model: 10AA002CUS

This is a lovely system.

The loudest part in this thing is the 2.5″ HDD. After replacing it with a Samsung 850 EVO SSD, this little box is virtually silent.

My only worry is that there is no cooling of any sort attached to the chipset. Although it is located in an area where there is ample airflow, a simple aluminum heat spreader will make me feel much safer.


Internals and Memory and SSD Upgrade

The system is a base model with 4GB RAM and 500GB HDD (a staple in numerous Lenovo products). I replaced them with 16GB CL9 G.SKILL kit and a Samsung 850 EVO.

Side By Side

The two systems are almost identical when it comes to form factor. Performance will be comparable, too, as both are based on 35W Haswell CPUs. Expansion capabilities are similar. Silverstone can

What’s similar?

  • Form factor
  • Performance. Both comfortably house a 35W Haswell CPU. No discrete graphics.
  • Can take a 2.5″ drive.

What’s different?

  • M93p has room for a mSATA device, but a socket is not installed. A missed opportunity.
  • M93p matches traditional desktop experience with headphone and microphone jacks and two USB 3.0 ports on the front panel. PT13 has only two USB 2.0 ports, although with this kind of form factor it might not be difficult to use the rear I/O ports.
  • M93p has more elegant Wi-Fi antennae than my own antenna solution on the PT13. Due to port layout, when the PT13 is placed horizontally, the bottom antenna has to point sideways.

DIY or Pre-Built?

In this case, pre-built. There is usually a fun factor associated with DIY, and even if custom-building ends up costing more than a pre-built, I would still favor DIY. Due to the different specifications, I cannot directly compare prices of these two systems. But what is certain is that custom-building will not be any cheaper in this particular case because I came across a good discount on the M93p.

The height of motherboard standoffs on the Silverstone PT13 is a significant design flaw. An additional 3-5mm would eliminate many compatibility issues and greatly improves user experience with this case while maintaining a slim form factor.

Overall, the pre-built M93p is a much more elegant mini PC.