HP ProBook 430 G5 Mini-Review

• non-glare screen
• VGA and HDMI for connecting to an external display
• Ethernet and WLAN
• 2 USB-A and 1 USB-C connector, and an extra power connector
• relatively small (20mm x 326mm x 236mm, but not small enough for the laptop confinement of my backpack, which houses a 11.6" Lenovo E130). Indeed, the 14" model is just 10mm wider and 2 mm deeper, and currently the same price, and may be preferable to many.
• As a consequence of that, no Numpad, and the alphabetic part of the keyboard is not shifted to the left.
• 1920x1080 display (many of the projectors out there now support 1920x1200).
• Available with 256 GB SSD and 8GB RAM at an ok price (and you can install 8GB more if you don't want to pay the premium for the 16GB model).
• One version is available without OS at a lower price; unfortunately, currently we only get the (outdated) Core i5-7200U with that deal.

• It's not clear if the battery is replaceable at all.
• A smaller laptop (maybe a ProBook 420) would be nice: Essentially, the keyboard determines the minimum size, and this laptop is 30mm wider than the keyboard, and the keyboard has one extra column that would be better left away (see below). Unfortunately, the smaller laptops available these days lack connectors, because the manufacturers also want to make them extra-slim.
• The keyboard has some cursor keys to the right, and in particular the Pos1 (Home) key to the right of the Backspace key, and I constantly hit Pos1 instead of Backspace. I can fix that by telling the X Window System to produce Backspace for the Pos1 key, but it's less than ideal.
• The touchpad lacks keys. I use an external mouse in most cases anyway, but now that becomes pretty much the only option.
• The USB-A connectors require unusually much force to insert devices (tested with two USB sticks and a USB mouse).
• It would be nice to have an option to get a US keyboard instead of the German one in the model we can buy here.
• Comes without a proper manual. In particular, there is no information on how to open the unit to replace RAM etc, not even on the supplied CD. But there is an interesting End-of-Life disassembly guide.
• It would be nice if we could buy this computer with a Ryzen5 2500U, but we don't get this option. However, there is the HP ProBook 645 G4, which can be had with one of several Ryzen Pro CPUs. There are also some other HP laptops with these CPUs (starting at <EUR 400, but the HP 15-db0500ng is reported to have low performance because it is power-throttled to 6W), if you don't care for VGA and HDMI.

We ran Ubuntu 17.04 and 16.04.3 from a USB stick, and tested various functions:

• VGA and HDMI worked fine with our projector. On first connection, I was in the dual-screen mode, and then, with the press of a keyboard button could cycle through mirror mode, external-only, internal-only, and back into dual-screen. VGA only gave me 1024x768 and 800x600 as options, but I have not tested how much of that is due to the projector, how much due to Ubuntu, and how much due to the laptop.
• Connecting the laptop to a 3840x2160 (4K) screen worked via HDMI, with the screen reporting 30Hz frame rate.
• Sound worked, both the speakers (not that great, as usual), and the headphone jack.
• The keyboard has lighting, with the light shining through the slits between keycaps and the base when I sit in my usual position; not sure if I would really find that helpful in the dark. When I sit closer, it works as intended.
• Suspend (to-RAM) works, by pressing the suspend key (closing the lid does not do it). Resume works, by pressing the power key; you can also set up the BIOS to start/resume the laptop on opening the lid.

  In our few tests of suspend, we had one case where the LAN was not connected (and not working) after resume, and we found no way to fix this except by doing another suspend and resume (which fixed the problem).

• In about two hours of doing backups with Clonezilla (which produces a full CPU load, in addition to SSD load, and USB load, and the power draw of a 2.5" HD during one hour of backuping; so overall quite a high load), the battery charge fell by about 80%. Recharging was predicted to take 1.5h, and after about 1h, the charge was at 89% (from 15%).
• Not (yet) tested: idle battery life, card reader, camera, microphone, USB-C.

One interesting aspect was the clock frequencies of the CPU under various loads, with mains power and when battery-powered (the BIOS says that Turbo is disabled when on battery (that can be turned off), but the results below contradict this). We generated load with different numbers of yes >/dev/null processes (integer-only load), and found the following clock frequencies (with some occasional funny results):

     MHz   MHz
load mains battery
  1  3400  3400
  2  3000  3000
  3  2700  2540
  4  2400  2300
  5  2300  2300
  6  2200  2300
  7  2200  2200
  8  2100  2100

Note that the Core-8250U has 4 cores and 8 threads, so load 5-8 uses just hyperthreading on the same 4 cores.

The clock reaction to increasing or reducing the load was usually within 1s, so it is probably power-target-based or load-based, not temperature-based. We did these experiments for at least 10 minutes, but the clock rates were apparently not affected by the temperature buildup for this workload. The fan, which was off (or at least inaudible) at idle did spin up after the load (even just load 1) warmed the CPU up. Spinning up and down was gradual and not very loud, so not as annoying as the fan on my Lenovo E130.

Another performance test was to perform 1000x1000 double-precision matrix multiplication using libopenblas with varying numbers of threads, performing 100 runs between stretches of idleness.

        mains
threads MHz   GFlops
  1     3084  25.8
  2     3360  39.6
  3     3227  43.8
  4     3099  44.6
  5     3066  40.0     
  6     3009  40.6
  7     2957  41.4
  8     2892  41.8

The relatively low gains when going from 2 to more threads despite relatively high clock rates makes me suspect that the benchmark becomes memory-bound in that setting (each of the three 1000x1000 matrices involved consumes 8MB, and this CPU has 6MB L3 cache), and all these additional threads do is increase the proportion of time that they are waiting for data from memory.