René Rebe

With all the reviews about Bulldozer performance, I wonder how much is to be attributed to Intel’s compiler not generating latest, greatest, vectorized code for AMD CPUs, …

I still believe that Bulldozer delivers excellent server performance, especially when it comes to hardware assisted virtualization, and that desktop performance would look better with unbiased benchmarks, (and a better “core package” aware Window process scheduler) …

I got quite some CPU cycle requirements. For some time now I’m waiting for AMD to deliver sub 100 Watt (e.g. 95W) CPUs, but unfortunately the 95W editions of the Phenom II X6 1055T and 1065T are nearly impossible to come by (except you are an OEM ordering thousands of them). So I got a test system with the regular, 125W 1055T, and it just keeps running too hot.

While I’m still waiting for the Bulldozer to appear, and in a 95W flavor no less, I decided Sunday is a great day to experiment with undervolting the aging, hot silicon I got at hand. Actually it turned out the beast of a silicon I got can be undervolted by huge margins, from the factory settings:

NbVid NbDid CpuVid CpuDid CpuFid UNb CpuMult UCpu PCore
P-State 0: 32 0 6 0 17 1150.0mV 16.50000 1475.0mV 23305mW
P-State 1: 32 0 14 0 12 1150.0mV 14.00000 1375.0mV 20625mW
P-State 2: 32 0 18 0 6 1150.0mV 11.00000 1325.0mV 15370mW
P-State 3: 32 0 22 1 14 1150.0mV 7.50000 1275.0mV 10838mW
P-State 4: 32 0 26 1 0 1150.0mV 4.00000 1225.0mV 6738mW

Down to so far stable:
(more…)

Some time ago I got a black NEC display which comes with four video inputs: VGA, 2 DVI and even DisplayPort as well as USB hub with two upstream ports. As I found no setting available on the monitor to change the USB upstream port to use, I usually just changed the USB cable when I had another computer for some testing on my desk.

However, today, I found out that there is a NEC MultiProfiler setup utility which allows to permanently assign dedicated USB ports per video input. This way I finally got a full KVM switch inside the monitor, assigning the first USB port to the DisplayPort, and the second USB port to all the other video inputs, used for temporary testing of various stuff.

Just gave it a quick spin at a local store. quite nice so far, know and worked with QNX since the mid 1990s. But how the heck to you get out of an App, e.g. back to the home screen? Tried all kind of gestures, touched everywhere - nothing intuitiv worked

Update: Aha - touch sensitive bezel: swipe on the border, …

ioreg -lw0 | grep IODisplayEDID | sed “s/.*= .//” | xxd -p -r | strings -6

B… = AU Optronics
LT… = Samsung
LP… = LG / Philips
N… = ChiMei

So for some time now I’m searching for the perfect ultraportable (laptop). Tables do not really cut it, even got an iPad to test things, but productivity wise they are not too great to get things done. As I need to get things done, I require some kind of grown up notebook. All the latest Apple machines are not too pleasing either, either cold (on power-up) and too hot during use hard edged aluminum case, and glossy window glass mirror displays, … not to mention the ridiculously huge and space wasting MacBook Air screen bezel, …

The Lenovo X220 is not all that perfect either, same lagging Intel graphics (among others no OpenCL, …) and additionally I just noticed a setback in their display configuration:

The former X200/X201 spotted a 12.1″ 1280×800 display, and it’s ultra-portable cousin X200s/X201s even featured a: 12.1″ 1440×900 (PDF) - now with the “all new” X220 even the Premium HD display only features a mere: 12.5″ 1366×768 pixels, … (PDF)!

This is not only a lower dpi resolution (pixels per inch), it also cuts away enough vertical pixels to make it seriously less useful for professionals with remote screen sessions, and virtual machines. More than the last millennium’s 786 vertical pixels (remember when 1024×768 became standard?) really are a blessing when you want to have your operating-system’s menu bar, and window deco around your windows and generally avoid scrolling in your VNC, RTP, X11 session or virtual machines.

Doing some research on this topic I also spotted that the X220 IPS screen appear to have some ghosting issues, …

Dear manufactures: I do not need a professional computer (display) optimized for consuming cheap Hollywood (or Bollywood) movies. If the mankind is supposed to live on some more centuries, we certainly also have to get some work done, not just hang on to consume other’s stupid videos all days. And even for consuming a decent movie every now and then, I’d get myself a decent TV for that. And with 16:9 LCD TV’s I noticed most high quality movies, on BluRay and such, are not even 16:9, but more like 21:9, …

So, can we please get professional grade, matte, 16:10 display, with at least 800 vertical pixels back to get some serious work done?

So you got an “older” (pre 2011) MacBook Air with read-only USB recovery thumb-drive (stick)? Well, turns out it is only read-only by some firmware lock bit. Just run:

sm32Xtest.exe

On your favorite Windows (virtual-) machine to toggle the read-only bit. You now can use it for your personal data, or writing the Lion installer disk image to it to gain a Lion Recovery USB key, just as you like.

Yesterday, my father and I have been to the vintage car gathering (Oldtimer-Treffen) at the HefeHof, Hameln (Germany). Starting with nice sunshine I got some great shoots to share:

… more in the whole gallery

Since the 1st generation iPhone I enjoyed using some V-moda Vibe in-ear headset. At the time the V-moda Vibe was one of the first iPhone compatible headsets with microphone and good sound quality.

Unfortunately, as usual, the cable started to break just over the TRS plug’s bend protection. Attempts to save the headset by soldering a new 4 pin TRS plug proved a little difficult: soldering the tiny 4 pin ⅛ inch TRS connector is possible, but the fibre enforced wires make it pretty difficult. One has to carefully separate the fibre out of the copper, and even then getting solder onto the paint isolated copper wires is a tedious task. And all too often have signal crosstalk problems in the end, due to the now heated and dissolved isolating wire coat, … especially interfering the (i)Phone’s microphone ring detection, often leaving the microphone and remote button controls unfunctional. Often it even works at first, until the cables are cramped into the connector when the plug is screwed together.

In the end I decided to better just get new set and started an endless Google search and local shop listening test. I found most offered headsets either plain ugly (sorry folks!), or excessively overcharged, especially when lacking in sound quality. Some models from the German company Sennheiser would have been a nice choice - if just their cable control with microphone plastic enclosure would be more visually appealing.

Especially lacking where the excessively overpriced Shure SE535 and friends. For over 300 bucks the advertised musical professional headphones can not please my musical amateur sense of hearing: For one in a local shop listening test they failed to deliver any bass (low frequencies) to speak of at all, … and thus an extremly unbalanced frequency range overall.

In the end of the lengthy selection process (why can manufactures not just design, build, and sell the one perfect headset?) I ended up with a Denon AH-C560R. They do not only look very good, with their minimal, no-frills design (that could be out of Cupertino), for just about hundred bucks they deliver an well balanced frequency range, with definitely more bass compared to the expensive Shure series.

Of course the Denon also sounds way more balanced than the over 3 year old V-mode Vibe - maybe due to Denon having more audio design experience being a well known audio brand for many centuries. The V-mode had more bass, though - but overall the Denon sound more balanced, with clearer mids and highs. (Other reviewer would now go all lengths over starting to hear all sort of details, percussions, accents not being possible to hear with another headphone before, …)

Oh, by-the-way, I also found the Nox Audio Scout headset’s design VERY appealing, I even delayed the purchase some months to wait for their release, … However reviews, such as the one from Engadget where not too keen about their audio quality, and given that they are (still not) yet sold in Germany the shipping costs from the US where just too heigh to rectify trying them out myself, … Maybe I grab them for cheap when I am in the US the next time.

It will also be interesting to get a ear on the Bowers & Wilkins C5 - though I am not too sure if I will find such a huge & heavy tube comfortable.

Since Apple migrated to the energy-hungry Intel x86 CPUs some years ago Macs got quite some overheating, thermal throttling issues. For example you will find many compact aluminum Macs to become so hot, that you would barely want to touch, or use on your lap, with the miniature fans spinning at full pace.

The bad is that Mac users typical will not even notice that the (Intel) silicon will even start to emergency throttle down. They will only notice the machine becomes less “snappy”. Linux on the other hand will happily log the MCE to your syslog instead:

CPU0: Temperature above threshold, cpu clock throttled (total events = 794)
CPU0: Core temperature above threshold, cpu clock throttled (total events = 1)

If my aging, non-unibody, MacBook Pro would not throttle that much it would still be a perfectly reasonably powerful machine to use - even as professional. But as it became so annoying I decided to write a little benchmark too that logs the performance over time. When freshly booted this MacBookPro3,1 will start to throttle down after just a minute! And you will notice another spike of throttling where I started another benchmark instance on the second core, …

However, I think when I purchased the machine back in 2007 it was not that bad, I have the feeling it became worse when Apple exchanged the logic board due to the faulty, and failing NVidia chip, … maybe something (fan, heat-sink or -pipe) was not re-aligned perfectly, or too much thermal paste applied, …

I experienced this throttling with all MacBooks and iMacs in the last years. I just tested the latest (mid-2011) MacBook Air at a local shop which thanks to the Sandy Bridge Core CPU does finally not show this symptom that badly. They intentionally choose the lowest performance Ultra-Low-Voltage CPU for a reason, … Though thanks to the advent of Intel’s Turbo Boost it shows fluctuating performance levels, too. One could argue it is an publicly advertised thermal throttling feature

Whether due classic thermal throttling, or TDP (Thermal Design Power) based Turbo Boost: for researchers this means any such CPU is out of question for scientific performance measurements. A fixed-frequency CPU without funky throttling and boosting as well as a BIOS’ SMM (System Management Mode) not interfering (too much) is a must. Unfortunately, the later is hard to prove and avoid, though.