Disqus - Latest Comments for lhl

Re: AMD flagship Radeon RX 7900 XTX GPU now available for $844

lhl — Fri, 26 Apr 2024 10:57:47 -0000

A 4080 only gives you 16GB of VRAM, so for running large AI models, it will be at a disadvantage vs a 7900 XTX (the extra VRAM in particular is the biggest requirement). RDNA3 cards all have HIP/ROCm support now and you can run llama.cpp and derivatives (Ollama, Jan-ai, LMStudio, etc) at very fast speeds (~100 tokens/s for a Q4 7B model) w/ the 7900 XT/XTX. For AI, the 4090 is superior in every way, but also at 2-3X the cost.

Re: This is What a Vision Pro Competitor From Meta Could Look Like

lhl — Mon, 05 Feb 2024 13:04:16 -0000

In Lanman's talk he mentioned the Mirror Lake concept design included a BOM/component list, all of which could be sourced today. He also stepped through the CAD diagram which showed the the display element labeled as a "laser backlit LCD" - I did some searching and sure enough, JDI was showing off a 2K laser backlit display prototype for VR HMDs back in 2021 (as a free bonus you get 97% BT 2020 color gamut), so I don't think production of HOEs is quite as far-fetched as you posit.

I think VAC eye-strain/cognitive load is very under-appreciated, since there have been decades of research showing that it *is* a big deal for a lot of people, especially if the goal is to spend all day in a virtual workspace.

Personally, I'd rather have electronic varifocal (DeepFocus was open sourced *6 years ago now*, AFAIK the PDL/half-wave plate system is pretty well baked now as well) and I'd be OK skipping the holograms/reverse pass-through if we could get to 60ppd and varifocal (eg, I'd be happy if a Butterscotch Varifocal were available for sale, assuming you could get a proper windowing system and the ability to run Desktop apps in more than a single monitor).

Re: Motile M142 Cheapo Linux Laptop Notes

lhl — Wed, 05 Feb 2020 18:11:25 -0000

Yeah, this is controlled in the BIOS I believe, I don't know how to adjust it.

Re: How To Use MKL with AMD Ryzen and Threadripper CPU's (Effectively) for Python Numpy (And Other Applications)

lhl — Sun, 08 Dec 2019 17:35:36 -0000

Since I got curious, Here are some test results on my Ryzen 3700X system (benchmarked using this little script by Markus Beuckelmann that I can't seem to link but should be easy to find by searching that name and numpy BLAS if anyone wants to replicate). My results:

# blis 0.6.0 h516909a_0 Dotted two 4096x4096 matrices in 2.30 s. Dotted two vectors of length 524288 in 0.08 ms. SVD of a 2048x1024 matrix in 0.94 s. Cholesky decomposition of a 2048x2048 matrix in 0.24 s. Eigendecomposition of a 2048x2048 matrix in 6.36 s. # AMD BLIS 2.0 Dotted two 4096x4096 matrices in 2.33 s. Dotted two vectors of length 524288 in 0.08 ms. SVD of a 2048x1024 matrix in 0.78 s. Cholesky decomposition of a 2048x2048 matrix in 0.23 s. Eigendecomposition of a 2048x2048 matrix in 5.84 s. # libopenblas 0.3.7 h5ec1e0e_4Dotted two 4096x4096 matrices in 0.41 s. Dotted two vectors of length 524288 in 0.02 ms. SVD of a 2048x1024 matrix in 0.55 s. Cholesky decomposition of a 2048x2048 matrix in 0.14 s. Eigendecomposition of a 2048x2048 matrix in 5.53 s. # mkl 2019.4 243 Dotted two 4096x4096 matrices in 1.53 s. Dotted two vectors of length 524288 in 0.02 ms. SVD of a 2048x1024 matrix in 0.51 s. Cholesky decomposition of a 2048x2048 matrix in 0.29 s. Eigendecomposition of a 2048x2048 matrix in 4.79 s. # export MKL_DEBUG_CPU_TYPE=5 Dotted two 4096x4096 matrices in 0.33 s. Dotted two vectors of length 524288 in 0.02 ms. SVD of a 2048x1024 matrix in 0.29 s. Cholesky decomposition of a 2048x2048 matrix in 0.15 s. Eigendecomposition of a 2048x2048 matrix in 3.29 s.

I was setup AMD BLIS 2.0 by simply setting up regular BLIS and extracting the binaries into that conda environment's lib/include and it seemed to work hunky dory (and was a little faster, but not better than OpenBLAS or even the gimped MKL in these tests).

Re: How To Use MKL with AMD Ryzen and Threadripper CPU's (Effectively) for Python Numpy (And Other Applications)

lhl — Sun, 08 Dec 2019 02:38:59 -0000

I don't know anything about AMD BLIS, but the default BLIS package is fairly easy to install in Anaconda:

conda create -c conda-forge -n numpy-blis numpy "blas=*=blis"

And based on Zen1 benchmarks, it might significantly outperform OpenBLAS: https://github.com/flame/bl...

Re: 1 Year Personal Health Intervention Summary

lhl — Sat, 21 Sep 2019 19:05:39 -0000

I haven't seen anything on ketosis and hair loss, although there's frequently temporary hair loss with weight loss (Telogen Effluvium). I suspect to the degree that there's hair loss it might also be triggered by changing hormonal levels (eg, higher DHT?).

You can look up the "Brain" category of my nutrition references, but in my research I found a fair amount of evidence suggesting that ketosis confers beneficial/neuroprotective effects (whether it's TBI, oxidative stress, hypoxia, neurodegenerative diseases, or even general cognition) but the evidence is still emerging - generally, I think there's a huge amount of bio-individuality and people should learn to listen to what their body is telling them and go with what makes them feel best, but to do less generalization.

Keto as an eating pattern seems to work especially well for specific phenotypes - eg, those exhibiting obesity, central adiposity, poor glycemic control, or that are otherwise exhibiting signs of carbohydrate intolerance. It might not be for everyone. But, I do think that long term it's probably a healthier option than most others, and longer-term studies are emerging. The Virta Health trial is going into its 3rd year with improvements in virtually every surrogate marker of metabolic health (https://www.virtahealth.com... , June 2y report: https://www.frontiersin.org... ), the FASTER trial tested VLC athletes that avged 20mo (9-36mo) on the diet: https://linkinghub.elsevier... and this paper was published with a cohort where 29% was on VLC for >36mo: https://www.oatext.com/long...

IMO Carbs aren't "as important" for health, simply because it's there's no essential carbohydrates (vs essential fatty and amino acids) - you can produce all the glucose/glycogen your body needs endogenously, but I'd agree that it seems like most people can healthily have reasonable amounts un-refined/cellular starch and sugar and my personal goal for being healthy has been to have the metabolic flexibility to eat carbs when I really want (which I do ocassionally) or even the rare crap meal/junk food (but recognizing that's probably not the healthiest thing).

The future of chronic/metabolic health is precision or personal rather population-wide, but even without rigorous instrumentation, I think people get much too wrapped up in trying to make rules that apply to everyone all the time when they clearly don't. Try some stuff, do more of what works for you, less of what doesn't. That's probably good enough.

Re: Emma Rourke reviews Horizon: Eat, Fast, and Live Longer

lhl — Wed, 10 Oct 2018 18:01:33 -0000

It's interesting reading this review 6 years later when it's becoming increasingly clear from human trials that the benefits of fasting do line up with the animal model testing (from cancer DOI:10.21037/12654 DOI:10.1007/978-3-319-42118-6_12 DOI: 10.1016/j.arr.2017.02.001, to exercise/weight loss DOI:10.3233/NHA-170036 DOI:10.1038/ijo.2010.171 DOI:10.1080/21623945.2015.1025184 DOI:10.1002/oby.21581, to overall health DOI:10.1126/scitranslmed.aai8700 DOI:10.1016/j.cmet.2013.12.008 DOI:10.1038/ncomms3316 DOI:10.1038/oby.2010.54) despite the lack of coverage of some of the other metabolic effects being covered (autophagy being the new hotness). There's a lot of ongoing research, but here's a 2014 overview at least touches on most of them: 10.1016/j.cmet.2013.12.008

Re: Large Capacity Travel Battery / Power Bank

lhl — Tue, 02 Oct 2018 17:45:17 -0000

Laptops all charge via DC power, typically between 12-20V depending on the model. All batteries output DC. If you use an inverter, you are converting from low voltage DC to 120V AC that your laptop charger then has to convert back to DC for your laptop to charge with. You lose efficiency for both these unnecessary conversions. This is doubly bad if your inverter is using a modified/non-pure sine wave for the AC. You can search for “AC to DC conversion losses” or “difference between AC and DC power batteries” or the like to find out more introductory information on how that all works.

Re: The Best Portable AC Power Supply (So Far)

lhl — Mon, 20 Aug 2018 08:33:52 -0000

Just as a followup, I did my own product review recently (July 2018). My conclusion largely separates out first into whether it needs to be TSA/IATA flight friendly (if so it should be <100Wh), and then breaks out into whether you need maximum sustained wattage, an inverter, or want the most bang for your buck/weight. I've included my spreadsheet which lets people decide based on their own needs: https://randomfoo.net/2018/...

Re: Oculus Go, Mirage Solo, and Vive Focus Standalone Headsets Compared

lhl — Tue, 01 May 2018 07:28:42 -0000

Your original post was asking why someone would spend more. Your second response was arguing that people just won't know the difference or care - two very different things. Most people will (have been getting) terrible mobile VR - they watch some badly done stereoscopic porn and some ultra-low bitrate youtube 360 videos and go well, I don't know what the fuss about and the headset goes into the gadget closet and we'll have to wait for Apple to "invent" VR in a couple of years for them to really experience what actual VR has to offer. As a 3DOF device, I don't think the Go really changes that or is really doing the future VR market any favors, but ¯\_(ツ)_/¯

Re: Oculus Go, Mirage Solo, and Vive Focus Standalone Headsets Compared

lhl — Mon, 30 Apr 2018 20:19:18 -0000

The $200 option only has 3DOF (rotational) not 6DOF (positional) HMD tracking, which is quantum leap of difference (something that lets you turn your head around vs walking around in a space). GearVR-level experiences aren't terrible, but will make you go "hmm, that's neat" rather than convincing you that VR really might be the future of computing (which IMO, 6DOF does). You should try out both types of VR before assuming they're the same type of experience.

With the Vive Focus you are paying a bit more for better resolution, contrast/motion pixel quality (w/ OLED) and for physically adjustable IPD, which seems fair, in terms of price.

Re: Waterproof vs Water Resistant. What Do I Need?

lhl — Thu, 11 Jan 2018 06:58:24 -0000

I travel with a lot of gear through a lot of wet weather so solid waterproofing in my bags has been a high priority for me. I went through a bunch of bags until I got to the Ortlieb MountainX 31, which is going on its third year for me. I've been super happy with it, so I thought I'd give it a shout out. While it's "only" IP64 rated, it is seam welded, uses a PU-coated nylon that is 100,000mm rated (and has taken a tremendous amount of punishment), and has a beefy transverse TIZIP Masterseal 10 zipper. It hasn't had problems keeping everything dry in hour long walks in heavy rain and heavy snow, or sitting in standing water. I've kept an eye out for anything that's built as tough that might have slightly better internal organization (although since I've traveled through a lot of sketchy locales, I actual appreciate the lack of external access), or honestly, just a vertical zipper for easier access w/o having to pull everything out (sadly, the way the transverse zipper opens/divides isn't quite as convenient as I'd originally hoped) but I have yet to find anything that both passes muster on the weatherproofing side and offers significantly better features.

Re: Olympus Unveils 17mm f/1.2 and 45mm f/1.2 Lenses for Micro Four Thirds

lhl — Fri, 27 Oct 2017 05:37:49 -0000

The lenses aren't cheap (priced about to what the market will bear I'd say) but one thing to remember is while you're listing DoF equivalents, at the end of the day, they are still actually f/1.2 lenses for light gathering which is a big deal, especially w a m43 sensor. You're paying a bit for an optical system that gives you different characteristics than for FF, but that's just part of the tradeoffs.

Re: The Best Portable AC Power Supply (So Far)

lhl — Thu, 28 Sep 2017 06:49:22 -0000

I enjoyed reading this article, but I continue to wish Wirecutter would include a feature/spec comparison grid, since different people have different requirements and many specs are hard/impossible to find online (for example, pass-through charging or weight and volume of the chargers). For myself, I have a spreadsheet that takes into consideration some things that weren't quantified at all: charging V/A/W ranges, battery dimensions/volume, DC output (specifically max wattage, and voltage ranges/max amperage), types of USB (some have smart/quick charging, some don't) and Wh (eg, anything above 100Wh is less than ideal for air travel as they require airline approval) and Wh/$ and Wh/kg metrics.

FWIW, when I did my research last year I ended up choosing the RAVPower 23000mAh (looked like the same model as the Poweradd Pilot Pro2 23000mAh). For $90-100, this 85Wh device weighed only 560g (152Wh/kg, 0.95Wh/$), had 2 "smart" 2.1A USB ports, and support for 90W (4.5A) DC output at 9V, 12V, 19V, and 20V, was only 0.4L in volume, and supported pass-through charging.

My ideal 2017 version would have a 27Ah capacity (99.9Wh), support USB-C/USB PD (and support for USB-C input charging), 2.4A USB 2.0 charging, a variable 9V-24V DC output (and maybe say 120W output) and if I were wishing for a pony, maybe with the ability to limit output current as well (my Mavic batteries want to charge at 13.05V/6A so I need an additional voltage converter with current control).

Also, while I know it's part of the title, personally, I don't see much of a point for an inverter - everything I (and I suspect most people) need a high voltage battery for, like laptop charging, battery charging, powering other 12-24V electronics, all run on DC anyway, but if someone needs it, I think having the inverter as a separate add-on is a better choice.

Re: MSI Radeon RX Vega 64 Air Boost pictured

lhl — Fri, 22 Sep 2017 21:35:25 -0000

Why would you recommend Vega 64 for Linux? You either need to use the AMDGPU-PRO driver which only works w/ RHEL 7.3, 6.9, Ubuntu 16.04.3, or SLED 12SP2 (Linux 3.10, 2.6 (!), 4.10, 4.4 respectively) or you have to run w/ amd-mainline (off of 4.11 or 4.12), which while it supposedly has ROCm patches, does *not* support OpenCL. For amd-mainline, you will also need to be running mesa-git and LLVM 5.0+. For OOTB support, you'll need to wait for Linux 4.14 and Mesa 17.3. (November maybe?)

I'm all for supporting AMD's open source efforts (and its one of the reasons I pre-ordered a ref 64 @ MSRP) and picking between similarly performing Polaris vs Pascal, I think going w/ Polaris for Linux is actually the way to go (if you could find one for a decent price), but I cringe a bit hearing about how great Vega might be for Linux from people that obviously haven't ever tried using it - maybe in a couple months, but right now, OOTB? It'll only work on a very specific set of distros/version numbers or if you put a heckuva lot of elbow grease in.

In Windows, I can't complain too much. w/ 17.9.x my card runs at 1530MHz @ 990mV (1100MHz HBM). I swapped in a Morpheus II and my Noctua 120mm fans run at +2dB (nearly silent on my open bench). My FSE scores are about 11.3K - a bit better than stock 1080, less than an OCd 1080. I actually can't complain too much about power usage once undevolted about 250W? (have to go off the wall since AMD doesn't have good board power reporting)

Re: Bloomberg TV Appearance

lhl — Mon, 22 May 2017 02:17:57 -0000

Just as a fact check, as of right now, the Bitcoin Dominance Index is at 46.1%. When you posted Friday it was wat 48.2%. The week before that it was at 56%. Basically, it's been collapsing dramatically (from a solid steady 85% or so) since March. Today marked the first time ETH POW pays more (has more $ security) than BTC POW and ETH/BTC is 45% and rising. Flippening in 2017 seems like a not so far out prediction (we'll see if this Segwit+HF thing turns out, but if UASF happens, it will be mayhem).

Re: Building a Battery Powered PC

lhl — Wed, 15 Feb 2017 02:31:36 -0000

The HDPLEX is built for PCs so you shouldn't need to do anything hooking up to the motherboard, etc (some people recommend making your own harnesses to make the cabling neater, but I'm lazy and just did extra cramming).

Re: DIY Backpack VR System

lhl — Fri, 30 Dec 2016 03:58:16 -0000

Hey Dani, I've been traveling. This link should help you if you're looking for DC PSU options: https://smallformfactor.net...

Re: DIY Backpack VR System

lhl — Mon, 03 Oct 2016 18:39:29 -0000

Probably less worried than all the other ways that electricity can kill you, be sure to read my previous posts on DC powering a system to make sure you're comfortable with soldering the leads etc. If you don't have any electrical/hardware experience, you may be better off buying one of the commercial options coming out soon like: http://vr.msi.com/index_VR_...

Re: DIY Backpack VR System

lhl — Thu, 15 Sep 2016 12:48:15 -0000

Yes you could double up batteries in series to get longer use times although you'd probably be better off adding a power controller (diode basically) that would allow battery hot swapping. You can power the HMD from the PC. You can check out my previous writeup on battery powering a PC, but using an inverter would give you triple power conversion losses and would be very heavy. It's up there with "strap on a UPS" in terms of terrible ideas. I wouldn't recommend it, but feel free to try it out if you want.

Re: Building a Battery Powered PC

lhl — Thu, 15 Sep 2016 06:01:31 -0000

@Zerofool Basically, I wouldn't worry too much about the relatively small overvoltage. It's only overvolted when the battery is at full charge anyway, which quickly goes down. If you are worried, you can just set your charger to stop charging at a lower voltage, which basically any balanced-charger should let you do.

Re: LattePanda 4G/64GB without Win10 product key

lhl — Fri, 19 Aug 2016 10:20:32 -0000

The UDOO x86 Ultra has everything you requested and more (Pentium N3710 w/ 8GB dual channel DDR3, M.2 B+E, SATA) but honestly at that pricing, and if you don't specifically need tons of GPIO, you could also either de-shell some NUC/Brix systems (or talk to any number of x86 SBC vendors if you're buying in actual volume) who can sell you something for about the same price.

Re: DIY Backpack VR System

lhl — Tue, 12 Jul 2016 11:36:27 -0000

The Samsung Gear 360 is probably the best bang/buck 360 camera currently. Personally, I think stereoscopic 180 degree video is probably more compelling than 360-degree monoscopic right now though, especially considering the resolution limitations both on the capture and streaming/playback side. There are a lot of custom rigs atm (mostly involving GoPros or fancier mirrorless rigs) but this is coming out soon and looks pretty neat: http://lucidcam.com/

Re: DIY Backpack VR System

lhl — Tue, 12 Jul 2016 11:33:28 -0000

Yes, I didn't do it (laziness finding the power connector) but you can route a 12V molex from the HDPLEX to a 1.3×3.5mm female connector to power the Vive.

Re: How fast Radeon RX 480 can be?

lhl — Fri, 01 Jul 2016 01:07:08 -0000

Alan, I occasionally drop in the eevblog, thanks for the invite. I do feel like the discussion has veered a bit, so let me just try to rephrase what I was trying to get across. The point I was trying to make isn't that the mosfet itself will suffer from thermal runaway or whether PDmax drops as temperature goes up (it's on the spec sheet), but that for a given amperage requirement required by the GPU core, that the VRMs will become less efficient at delivering that power as the temperature goes up and will take up a larger proportion of a fixed thermal budget (say 150TDP within a black plastic shroud). The PMC for the VRM should stop things long before anything starts melting.