Marc's Public Blog

However, when I got my thinkpad P70, although it also uses around 25W in typical use, which means plenty of extra wattage on a 90W power supply to charge the battery, the P70 was unfortunately designed not to charge under any condition unless it recognizes a power supply that's at least 135W (it ships with a 170W power supply, and it's a huge monster brick). I'm pretty mad at lenovo for that because they could totally have designed the P70 to charge at a slower rate from a 90W power supply, or at least when the laptop is sleeping, but no, even when it's sleeping, it will just not charge at all. Sadly, this means that the RAVPower 23000mAh Portable Charger Power Bank External Battery Pack I bougght, was able to power the laptop, but not charge it. I guess in this case, it's not a huge issue since energy would be wasted trying to charge the laptop battery instead of just powering it, but still, that was disappointing.

here, the pack is powering my laptop at 20V, 2.1A

The P70 will function off a 90W power supply by just not discharging its battery, and consuming around 1.5A at 20V (i.e. 30W), so that meant that not only I had to buy some bulky 135W power supplies (less bulky than 170W thankfully), but also that I was now unable to use my travel iGo 110W 12V DC power supply, which I use to charge in cars. For AC, I did buy a Lenovo ThinkPad 135W (Slim Tip) Replacement AC Adapter for lenovo ThinkPad T440p 20AN 20AW, Lenovo ThinkPad T540p 20BE 20BF: https://www.amazon.com/gp/product/B00HOMBO0M

But for car use, I was upset about the situation, so I read up and realized I only had to change the resistor in my barrel connector to slimtip adapter and that would likely allow my thinkpad to start charging from my 110W iGo power supply. The hard part was finding where the resistor was since I had to replace a small resistor with a bigger one (the other way around, I could have trivially added a resistor in series).

So, I started with the AC Charger Power Supply Adapter Converter Cable Cord For Lenovo ThinkPad : https://www.amazon.com/gp/product/B00T013J44 and had to find where the resistor was hidden. After cutting the cable in 2, I convfirmed it was on the slimtip side, so I had to take the plug apart until I found it.

After that, it was just a matter of adding a new resistor, and in the end, I added a resistor bridge, so that I could select no resistor, 550 Ohm (90W), 1kOhm (135W), or even 1.9kOhm (170W). For my laptop, though 135W was enough, and my iGo only delivers 110W anyway.

I added a amp/volt meter (RioRand 2in1 4.5-30V 10A Digital Voltage Detector DC Current Volt Amp Meter), so I can tell how much current is flowing and whether I might be exceeding the wattage of the power supply. When my laptop is running, and the battery charging, it's now using 5.6A (just about 110W)

So problem solved. I'm not super happy at Lenovo for having stupidly designed their Thinkpad P70 not to charge from a 90W power supply under any use case, even at reduced speed, or even with the laptop sleeping or off, but since I already had the laptop, I was stuck with it, so this little resistor hack did the trick. Hope this helps someone.

Oh yeah, for car use, instead of this old obsolete iGo brick, I made my own 12V-20V DC-DC converter, and you can read more about it on this page

We went up to the hike terrain on the ridge, and the top had some kind of icy powder, almost like shaved ice, interesting to ride. after that, it went kind of downhill a bit (ah!)

Be careful on the lifts :)

After a day of skiing, we had seen all the mountain, and kind of imagined how good it could have been given non icy snow :-

The part on nuclear energy was very well done, and included a fair amount of French nuclear reactors, France probably being the leading country in nuclear energy, and interestingly, I learned that France, and in turn most of Europe, recycles and reuses most nuclear waste to further get energy from it and reduce the waste to much smaller amounts. In the meantime, the US doesn't recycle waste, and has huge amounts sitting in what were supposed to be temporary cooling ponds, where it's more vulnerable to attack, while politicians are still fighting over whether that waste can be transported to its supposed final storage location in the middle of a mountain in Nevada. Go USA!

french poster selling radioactive cream, supposedly to make women prettier. Ooops...

let's not forget radium water you can make at home :)

I didn't get an atomic energy lab kit when I was a kid :)

But outside of nuclear energy, they had quite a good collection of planes and rockets:

atomic cannon, never had seen one before

The collection of cruise missiles and ICBMs was very good:

Hello! :)

the list of broken arrows, lost nuclear missiles, was 'interesting'

ICBMs have multiple nuclear warheads that get ejected on multiple targets

The first nuclear bomb, named "gadget", tried at the Trinity site in New Mexico

this was used to create fat man

and sadly ended up in Japan

welcome to New Mexico, the state of Breaking Bad and Better Call Saul :)

Is that a gun in your bag? Apparently the TSA finds many guns people forget in their carry ons...

As soon as I landed, Arturo came to pick me up and we went to the Albuquerque Museum of Nuclear Science and History (on its own page)

From there, we drove through Santa Fe towards Taos:

The next morning, we went snowboarding in Taos, in passable conditions (see Too sunny conditions at Taos Mountain page for details):

After skiing at Taos Mountain the 2nd day, we went to drive in downtown Taos a bit. We were surprised to see Kit Carson, from Carson Spur and Carson Pass around Kirkwood in California. That was a long way for him to go:

the magpie, aka the michoko bird :)

The next day, we elected not go to to Taos and just start driving towards Jackson Hole, but on the way out, we went to visit Taos Pueblo, an Indian reservation in Taos. It was deserted, but nice to visit:

We then went on our way, and stopped at a fun Gator park on the way:

nice teeth

nice turkey

On the way, we stopped at Leadville Airport, the highest airport in the continental US:

And then, we went back for a longish-drive and we got as far as Rock Springs before calling it a day. Arturo was a trooper there. Thanks to nexrad weather on my phone, we were able to hit minimal weather. Arturo spotted a very nice fox in the snow:

After a night in Rock Springs, we got up early and drove to Jackson Hole. The conditions were mostly icy on the first day, but better on the second day thanks to 4 fresh inches of power (follow the link for details)

After skiing in Jackson Hole, we went to the town of Jackson for a quick tour, and some food. Found a moose eating vegation in the restaurant's parking lot:

After 2 days of skiing, I figured I had gotten the best snow there was to get (the powder that just fell was going to ice up again), so I was able to get a flight one day early out of Jackson:

So let's be honest and say that it is a big a heavy laptop, but that was an acceptable tradeoff for me. CPU wise, it's actually no faster than the T540, but the big new thing is the 2 M2 slots in addition to capacity for 2 2.5" Sata drives, like the T540 (one goes in place of the DVD Burner using a special tray).

yes, it's big

the 2 M2 slots are on the right, and the 2nd drive goes under where the SSD is visible in this picture

size of M2 sticks compared to the SSD (with free shot of the 96Wh battery :) )

Comparison with the T540

So the P70 can currently house 5TB of storage and I was interested to see how well the M2 slots worked compared to the Sata ones under linux. First thing to note is that currently M2 slots can only house 512MB of storage each vs 2TB for the 2.5" Sata slots that have more room. Sadly, Lenovo is still not selling the Drive Caddy Adapter for the P70, but the good news is that you can buy this $17 Soogood 2nd HDD SSD Hard Drive Caddy Adapter Use For Lenovo Thinkpad T440p T540p W540p from Amazon, unscrew the little tab from the DVD Drive, screw it on the drive caddy adapter, and it'll work in the P70.

To try that out, I got the following (with price by GB as of 2016/02), in increasing price per GB: - 4.6c/GB: Seagate 2TB Laptop HDD SATA 6Gb/s 32MB Cache 2.5-Inch Internal Bare Drive (ST2000LM003) - 30c/GB: SATA6G: Samsung 850 EVO 2 TB 2.5-Inch SATA III Internal SSD (MZ-75E2T0B/AM) - 33c/GB: M2/SATA Samsung 850 EVO 500 GB M.2 3.5-Inch SSD (MZ-N5E500BW) - 64c/GB: M2/NVMe: Samsung 950 PRO -Series 512GB PCIe NVMe - M.2 Internal SSD 2-Inch MZ-V5P512BW

So it's interesting to note that SSDs still cost 6.5x more than a hard drive (actually I was surprised to see how cheap the 2.5" 2TB hard drive was). Next, it's good to know that M2/Sata SSDs cost about the same price per GB than full size Sata SSDs. And last, at twice the price, the M2/NVMe SSD is no bigger than the SATA M2 version, but clearly more expensive. It's supposed to be up to 4 times faster in bulk transfer rate due to the use of 4 PCI lanes, but I was curious to see how much faster it would actually be for real use with linux.

First, is looking at support. To make things interesting, I decided to make the NVMe SSD my boot drive. The Thinkpad bios of course supports it fully, but a big gotcha is that it'll only boot if you use a GPT partition with EFI. Setting that up from scratch was a pain, but I got through it, and it's out of topic for this post.

Next, is linux support. Thankfully linux has supported NVME for a while now. I just set CONFIG_BLK_DEV_NVME=y in my kernel so that I didn't have to worry about the module being in my initrd. Device partitions show up as /dev/nvme0n1p1 and so forth.

Now, the benchmarks. For my main filesystems, I have btrfs on top of dmcrypt, created with:

cryptsetup luksFormat --align-payload=8192 -s 256 -c aes-xts-plain64 /dev/device

In the tests below, I did used hdparm, iozone, and 2 kinds of dd, ddd with data, and dd0 copying just /dev/zero:

ddd test: sync; dd if=/mnt/ram/file of=file bs=100M count=100 conv=fdatasync; dd if=file of=/dev/null bs=100M
dd0 test: sync; dd if=/dev/zero of=file bs=100M count=100 conv=fdatasync; dd if=file of=/dev/null bs=1M

Let me start with the summary conclusions first, since this is what most people probably care about:

More detailled summaries related to the test results below:

So there you go. I realize that my test suite may not have been perfect, but hopefully the results are helpful to others. I'm hoping linux will get fixed, or that I can find a tunin g parameter to bridge the gab in cached IO speed between Sata 6G 2.5" and M2 slots. Below are test results in more details are you go down the page.

Here are test results for cached IO:

		SATA/M2 dmcrypt	 SATA/M2	NVMe dmcrypt	NVMe		SATA6GB/dmcrypt
hdparm -t	 534MB/s	 517MB/s	1307MB/s	2140MB/s	 534MB/s

ddd 10GB read	 550MB/s	 560MB/s	2000MB/s	2400MB/s	 550MB/s
ddd 10GB write	 500MB/s	 503MB/s	1300MB/s	1200MB/s	 506MB/s

dd with /dev/zero hits optimizations that actually penalize NVMe:
dd0 10GB read	   7GB/s	 6.7GB/s	 2.3GB/s	 4.4GB/s	 6.6GB/s
dd0 10GB write	 495MB/s	 503MB/s	 1.3GB/s	 1.3GB/s	 2.0GB/s

iozone -e -a -s 4096 -i 0 -i 1 -i 2 (cache makes Sata6G faster than M2, weird):
ioz read 4KB	1760MB/s	1790MB/s	 675MB/s	 766MB/s	7863MB/s
ioz write 4KB	 268MB/s	 298MB/s	 295MB/s	 291MB/s	 777MB/s
ioz ranread4KB	5535MB/s	7392MB/s	3185MB/s	7261MB/s	7892MB/s
ioz ranwrite4KB	 288MB/s	 329MB/s	 205MB/s	 381MB/s	 796MB/s

For comparison, I then used directio to bypass the caching layer:

iozone -I -e -a -s 4096 -i 0 -i 1 -i 2 (direct IO):
		SATA/M2 dmcrypt	 SATA/M2	 NVMe dmcrypt	 NVMe		 SATA6GB
										 dmcrypt notcrypted
		 btrfs		 btrfs   ext4	 btrfs		 btrfs   ext4	 btrfs     ext4
ioz read 4KB	 255MB/s	 303MB/s 408MB/s 303MB/s	 396MB/s 562MB/s 310MB/s 379MB/s
ioz write 4KB	 195MB/s	 238MB/s 344MB/s 257MB/s	 358MB/s 361MB/s 233MB/s 365MB/s
ioz ranread4KB	 305MB/s	 351MB/s 482MB/s 476MB/s	 699MB/s1434MB/s 309MB/s 475MB/s
ioz ranwrite4KB	 265MB/s	 223MB/s 392MB/s 260MB/s	 217MB/s 315MB/s 254MB/s 366MB/s

Details of each test, per type of drive;

===============================================================================
saruman M2 SATA 512GB encrypted btrfs

saruman:/tmp# hdparm -t /dev/mapper/cryptroot
 Timing buffered disk reads: 1604 MB in  3.00 seconds = 534.03 MB/sec

iozone -e -a -s 4096 -i 0 -i 1 -i 2:
                                                              random    random
              kB  reclen    write  rewrite    read    reread    read     write
            4096       4   257076   281089  1761711  6094733  6066754   290373
            4096     512   277108   295167  1588844  8426437 11128258   318731
            4096    4096   268940   308248  1760087  8062616  8377131   320802

iozone -I -e -a -s 4096 -i 0 -i 1 -i 2:
            4096       4    38626    45227   102236   111141    30936    64317
            4096     512   138467   128878   134674   137832   140067   126248
            4096    4096   195439   273100   255379   307300   305605   265093

saruman:/mnt/mnt# sync; dd if=/dev/zero of=file bs=100M count=100 conv=fdatasync; dd if=file of=/dev/null bs=1M
10485760000 bytes (10 GB) copied, 21.1761 s, 495 MB/s
10485760000 bytes (10 GB) copied, 1.49373 s, 7.0 GB/s

kernel 4.4.1 make -j8:
real    17m54.712s
user    126m26.620s
sys     6m21.948s

btrfs send/receive encrypted partition to non encrypted, 87GB: 10mn30

saruman M2 SATA non encrypted btrfs
-----------------------------------
saruman:/mnt/mnt4# hdparm -t /dev/sdc4
/dev/sdc4:
 Timing buffered disk reads: 1554 MB in  3.00 seconds = 517.93 MB/sec

iozone -e -a -s 4096 -i 0 -i 1 -i 2:
                                                              random    random
              kB  reclen    write  rewrite    read    reread    read     write
            4096       4   285020   297565  1739944  7434579  6605595   305785
            4096     512   310937   336617  1298278  3703511  5483860   299416
            4096    4096   298433   317101  1790911  7392988  7434579   337476
iozone -I -e -a -s 4096 -i 0 -i 1 -i 2:
            4096       4    47219    93497   118900   126065    39160    86462
            4096     512   214381   213388   194307   209215   206951   209289
            4096    4096   238792   221839   303768   352951   351342   223618
ext4 iozone -I -e -a -s 4096 -i 0 -i 1 -i 2:
            4096       4   119524   146035   150173   159105    53090   140697
            4096     512   358954   354810   366466   423088   419760   375542
            4096    4096   344087   398828   408259   478337   482569   392487

saruman:/mnt/mnt3#  sync; dd if=/dev/zero of=file bs=100M count=100 conv=fdatasync; dd if=file of=/dev/null bs=1M
10485760000 bytes (10 GB) copied, 20.8537 s, 503 MB/s
10485760000 bytes (10 GB) copied, 1.55651 s, 6.7 GB/s

kernel 4.4.1 make -j8:
real    17m55.612s
user    126m31.952s
sys     6m27.452s

********************************************************************************
saruman M2 NVMe 512GB encrypted btrfs

saruman:/tmp# hdparm -t /dev/mapper/cryptroot2
/dev/mapper/cryptroot2:
 Timing buffered disk reads: 3924 MB in  3.00 seconds = 1307.56 MB/sec

iozone -e -a -s 4096 -i 0 -i 1 -i 2:
                                                              random    random
              kB  reclen    write  rewrite    read    reread    read     write
            4096       4   284205   341651   742181  6195843  6178018   341101
            4096     512   314351   319573   864883  8865630  8902382   384993
            4096    4096   295741   201042   675234  3281854  3185110   205974
iozone -I -e -a -s 4096 -i 0 -i 1 -i 2:
            4096       4    80042    83160   122616   127129    41421    53963
            4096     512   168713   153333   167710   209923   198123   168026
            4096    4096   257968   258566   303023   490828   476440   260014

saruman:/mnt/mnt2# sync; dd if=/dev/zero of=file bs=100M count=100 conv=fdatasync; dd if=file of=/dev/null bs=1M
10485760000 bytes (10 GB) copied, 8.01494 s, 1.3 GB/s
10485760000 bytes (10 GB) copied, 4.63397 s, 2.3 GB/s

kernel 4.4.1 make -j8:
real    17m57.513s
user    126m58.360s
sys     6m25.164s

btrfs send/receive encrypted partition to non encrypted, 87GB: 7mn
(33% faster than Sata M2)

saruman M2 NVMe non encrypted btrfs
-----------------------------------
saruman:/mnt/mnt4# hdparm -t /dev/nvme0n1p4
/dev/nvme0n1p4:
 Timing buffered disk reads: 6422 MB in  3.00 seconds = 2140.38 MB/sec

iozone -e -a -s 4096 -i 0 -i 1 -i 2:
                                                              random    random
              kB  reclen    write  rewrite    read    reread    read     write
            4096       4   274808   271851   684271  2634219  2280673   177630
            4096     512   290191   336755   668196  3362795  4039655   184779
            4096    4096   291427   340345   766588  7355007  7261741   381768
iozone -I -e -a -s 4096 -i 0 -i 1 -i 2:
            4096       4    94814   117116   147645   159695    44075   108039
            4096     512   271130   267800   239969   325933   301841   271062
            4096    4096   358602   275933   396591   719099   699939   217665
ext4 iozone -I -e -a -s 4096 -i 0 -i 1 -i 2:
            4096       4   107281   200735   205900   263035    54832   124219
            4096     512   537478   374641   525060  1173664  1139338   558807
            4096    4096   361545   526137   562632  1483477  1434069   315883

saruman:/mnt/mnt4# sync; dd if=/dev/zero of=file bs=100M count=100 conv=fdatasync; dd if=file of=/dev/null bs=1M
10485760000 bytes (10 GB) copied, 7.90653 s, 1.3 GB/s
10485760000 bytes (10 GB) copied, 2.35863 s, 4.4 GB/s

kernel 4.4.1 make -j8:
real    17m54.221s
user    126m46.264s
sys     6m10.592s

********************************************************************************
saruman Samsung Evo 850 2TB SSD encrypted btrfs

hdparm -t
 Timing buffered disk reads: 1606 MB in  3.00 seconds = 534.87 MB/sec

iozone -e -a -s 4096 -i 0 -i 1 -i 2:
                                                              random    random
              kB  reclen    write  rewrite    read    reread    read     write
            4096       4   513924   738957  8586475  9144037  8017464   697665
            4096     512   772100   820362  9287391 10136778 10586522   840551
            4096    4096   719099   777517  7863339  8047509  7892238   796108

iozone -I -e -a -s 4096 -i 0 -i 1 -i 2
            4096       4    76626    47961    92886    80947    36063    63788
            4096     512   135087   138998   143127   150981   144393   132219
            4096    4096   233245   234058   310797   311552   309855   254080

ext4 iozone -I -e -a -s 4096 -i 0 -i 1 -i 2 (unencrypted)
            4096       4   118013   141212   130575   111534    42343   138654
            4096     512   336347   312192   332847   414404   424542   342707
            4096    4096   365227   364638   379298   484160   475122   366536

saruman:/tmp# sync; dd if=/dev/zero of=file bs=100M count=100 conv=fdatasync; dd if=file of=/dev/null bs=1M
10485760000 bytes (10 GB) copied, 5.23919 s, 2.0 GB/s
10485760000 bytes (10 GB) copied, 1.58287 s, 6.6 GB/s

kernel 4.4.1 make -j8:
real    16m4.305s
user    104m0.816s
sys     7m2.832s

front seat

read seat has more gauges :)

KSJC

Quick refueling at KTCY

group of RVs, taxing before takeoff

oops, this one didn't land so well...

and back in KSJC

Quick video of the acro bits:

Thanks Arnaud for the ride, nice flying :)

The next morning, I woke up to 2ft of powder, but very heavy winds. Sure enough the lifts obviously didn't open on time, but kirkwood did an amazing job getting things opened and cornice opened at 10:30, despite heavy winds at the top and a sheet of ice when you unloaded. Snow coverage was weird, the wind packed most of that snow, so it wasn't very fluffy, and in places it was icy as the entire 2ft of fresh snow had been blown off. Still, it didn't suck :)

did I say windy?

Coop came to see us in line to let us know about delays

and by 10:30, we were up :)

and by about 14:00, the wall got opened, which opened more nice runs

While the conditions were rough, it was very cold and super windy, but eh, you have to get the snow when you can :)

The next day was pretty much a bluebird, but very windy, so windy that they were not able to open chair 4 until 13:50:

I hiked up the ridge from the top of cornice

still super windy

finally the backside opened and I got 3 rides before they closed it for the day

Here are a few pictures:

very nice freshwater prawn

leafy seadragon just awesome :)

the weedy seadragon are so pretty

Jon, opening the miniconf

The Melbourne Hardware Hacking team who worked on this

Jon gave a cool talk on the hardware assembly machine he built to put those boards together, impressive:

Short of having a plant nearby, I concentrated on making pretty lights on the LED strip :)

blinkie achieved :)

I added my blinky code here: https://github.com/marcmerlin/ESPlant

Demo:

Like every year, it was great to see everyone again.

A few pictures from the conf:

where we stayed, Deakin, University

The robot miniconf had cool little robots:

During the radio miniconf, we did some beacon finding with yagis:

LCA still had a custom designed board that encodes HDMI video into open video formats on linux via USB:

Among the talks, tridge gave a demo of his new code for quadplanes (quadcopters that turn into planes) for the next challenge they're preparing for:

Catching up with people in the hallway track and evening parties was good as usual:

Stephen, keeping a great WiFi network working like every year

nothing beats seeing tridge in person to work with him on my ardupilot crash plane into the ground bug :)

After a week, it was all over again. We all had a great time, thanks all:

I hung out with the Melbourne Open Hardware Hackers after conf close, before getting ready for our great ocean road trip the next day: