A few years back NVIDIA created a dedicated cryptocurrency mining GPU, the CMP 170HX. This was a heavily restricted version of its flagship A100 datacenter accelerator, using the same GA100 chip. It was intended for accelerating Ethash, the Etherium proof-of-work algorithm, and nothing else. [niconiconi] bought one to use for accelerating PCB electromagnetic simulations and put a lot of effort into repairing the card, converting it to water-cooling, and figuring out how best to use this nobbled GPU.

Typically, the GA100 silicon sits in the center of the mighty A100 GPU card and would be found in a server rack, cooled by forced air. This was not an option at home, so an off-the-shelf water-cooling block was wedged in. During this process, [niconconi] found that the board wouldn’t power on, so they went on a deep dive into the power supply tree with the help of a leaked A100 schematic. The repair and modifications can be found in the appendix, right down to the end of the article. It is a long read to get there.

NVIDIA has a history of deliberately restricting silicon in consumers’ hands to justify the hefty price tags of its offerings to big businesses, and this board is no different. The plan was to restrict the peak performance of the board to only applications with the same compute requirements as Ethash, specifically memory-intensive algorithms. The FP64 performance was severely limited, but instructions were not removed. This meant the code would run really badly, considering what the GPU is capable of.

The memory was limited to 8 GB, despite some A100 cards hosting a whopping 80 GB. The strategy was to use fuses to limit the crucial instructions, particularly the FP32 FMA and MAD instructions, which are used for multiply-add operations and are crucial for general computing applications. Finally, the PCIe bus was nobbled to run only as a Gen 1 interface with a single lane. They reduced the lane count by removing the coupling capacitors on the PCB, which meant they could just be added later, but it’s still only a slow interface.

[niconconi] went into great detail benchmarking the instruction types, keeping their EM simulation application in mind. After a few tweaks to make it work, they determined it was a good purchase. This article is worth reading for all those hardcore GPU nerds!

If you need a primer on GPU mining, we’ve got you covered. Once you’ve understood proof-of-work crypto, perhaps take a look at Chia?

Thanks to [gnif] for the tip!

While classroom learning isn’t for everyone, one awesome benefit of the Internet is that you have a variety of college classes available to you, even if they aren’t for credit. You can virtually audit classes from institutions around the world on just about any topic you can think of. Of course, the topic we think of is practical electronics and that happens to be the title of a class from [Dr. Bill Newhall] of the University of Colorado. You can watch the first part in the video below. So far, there are two lectures available but more are coming as the class is ongoing right now.

[Dr. Newhall] is one of us. He’s a ham radio operator and a pilot, as well as an electrical engineer. This class is aimed at others who need to understand electronics in another context. It reminded us of the genesis of one of our favorite books — also from a professor — The Art of Electronics.

The course material promises to cover topics ranging from solar and battery power sources, power conversions, IoT and RF communications, sensors, and DC motor control. Of course, there will also be sections on microcontrollers and associated hardware.

Just like a real class, the first lecture has a lot of housekeeping information, but you might want to skim it anyway. But if you want to get to the electronics, the second video won’t disappoint. While it covers a lot of ground that is probably familiar to most Hackaday readers, it is a good review and there’s more coming in the future lectures.

With all the resources online, you can easily hack your own degree plan together. Having access to instructors like [Dr. Newhall] is exactly the point we were making about how the Internet allows you to leverage the best educational opportunities no matter where you are.

Docker and other containerization applications have changed a lot about the way that developers create new software as well as how they maintain virtual machines. Not only does containerization reduce the system resources needed for something that might otherwise be done in a virtual machine, but it standardizes the development environment for software and dramatically reduces the complexity of deploying on different computers. There are some other tricks up the sleeves as well, and this project called PI-CI uses Docker to containerize an entire Raspberry Pi.

The Pi container emulates an entire Raspberry Pi from the ground up, allowing anyone that wants to deploy software on one to test it out without needing to do so on actual hardware. All of the configuration can be done from inside the container. When all the setup is completed and the desired software installed in the container, the container can be converted to an .img file that can be put on a microSD card and installed on real hardware, with support for the Pi models 3, 4, and 5. There’s also support for using Ansible, a Docker automation system that makes administering a cluster or array of computers easier.

Docker can be an incredibly powerful tool for developing and deploying software, and tools like this can make the process as straightforward as possible. It does have a bit of a learning curve, though, since sharing operating system tools instead of virtualizing hardware can take a bit of time to wrap one’s mind around. If you’re new to the game take a look at this guide to setting up your first Docker container.

Hace instantes, el ministro de economía, Luis Caputo, anunció de manera oficial que el impuesto país para los importadores bajará del 17.5% al 7.5%, una reducción del 10% que incluirá cualquier tipo de mercadería que ingrese al país por el canal oficial (es decir, no de contrabando), pasará a costar -a la larga- un 10% menos. Para aquellos que no estén al tanto, todos los importados venían pagando el costo del dólar oficial además del 17.5%.

Varios mayoristas y comercios minoristas de informática del país ya venían anticipando esta disminución en dicho impuesto y lo más probable es que muchos comiencen reduciendo el costo de su stock actual en aproximadamente un 5%, hasta llegar en algún momento al 10%, dado que para muchos, 10% representa el total de sus ganancias -sobre todo en el caso de los distribuidores que tienen un margen bastante inferior.

Ante este anuncio, es muy probable que mañana -o incluso hoy- algunos precios en las tiendas de computación y sus portales web, ya se vean reflejado parcialmente la reducción del impuesto PAIS aunque, como ya mencioné previamente, van a pasar varias semanas (o incluso quizás uno o dos meses) hasta que la baja del impuesto impacte por completo en el stock actual de los comercios, ya que muchos tendrían que vender su mercadería al costo o incluso debajo del costo, y ciertamente no es el momento ideal para estar trabajando gratis o yendo a pérdida.

Con esta noticia, cualquier componente de PC, periféricos y todo lo relacionado a la informática, como también cualquier producto de todo rubro (una vez más, siempre y cuando se importe de manera oficial), gozarán de un importante descuento permanente, así que entre tantas malas, esta es una buena para los argentinos que buscan comprar un mouse o actualizar su computadora.

Esto beneficia en gran medida a los distribuidores y comercios minoristas que trabajan con productos mediante el canal oficial, al mismo tiempo que aquellos que lo hacen de manera ilegal sin pagar los impuestos correspondientes, se verán perjudicados al no poder acceder a esta reducción del 10% que solo regirá para importadores que giren los dólares correspondientes para comprar mercado en forma legal.

Esta medida no afecta a las compras con tarjeta (como por ejemplo comprar un juego en Steam), ya que la reducción es únicamente para importadores y no afecta a los impuestos del dólar tarjeta o turista. No obstante, el gobierno tiene planes de aplicar este 10% a dicho impuesto, pero no se ha dado especificado por el momento cuando ocurrirá la rebaja.

Importante!
A partir del lunes 2 de septiembre la alicuota del Impuesto País para la importación de bienes y fletes se retrotraerá del 17,5% al 7,5%.
Prometimos y cumplimos!

— totocaputo (@LuisCaputoAR) August 28, 2024

Acerca del Impuesto PAIS

El Impuesto para una Argentina Inclusiva y Solidaria, o PAIS, es un tributo que se debe abonar sobre ciertas operaciones en moneda extranjera. PAIS es un impuesto de emergencia que se aplicará a nivel nacional durante 5 períodos fiscales.

Para qué es

Lo producido por el impuesto será utilizado para financiar:

• Programas a cargo de ANSES y PAMI.
• Obras de vivienda social, del fideicomiso Fondo de Integración Sociourbana, obras de infraestructura económica y fomento del turismo nacional.
• Prestaciones a cargo del Instituto Nacional de Servicios Sociales para Jubilados y Pensionados.

Excepciones a la importación

• Mercaderías exceptuadas del Impuesto PAÍS – Ajustado a la VII Enmienda del Sistema Armonizado
• Mercaderías exceptuadas del Impuesto PAÍS – Sector Salud – Ajustado a la VII Enmienda del Sistema Armonizado
• Mercaderías exceptuadas del Impuesto PAIS
• Mercaderías exceptuadas del Impuesto PAIS – Sector Salud

Cuánto se paga

El importe a abonar se calcula aplicando los porcentajes que se indican a continuación:

30%

• sobre todas las operaciones alcanzadas, siempre que no se encuentren gravadas a una alícuota menor según se detalla seguidamente.
• Queda gravada a esta alícuota la importación de bienes suntuarios

25%

• sobre la adquisición en el exterior o en país (prestados por no residentes) de los servicios indicados en el anexo II del Decreto 99/2019.

8%

• Sobre los servicios digitales.

17,5%

• adquisición en el exterior o en país (prestados por no residentes) de servicios de fletes y transportes para importación y exportación de bienes, e
• importación de mercaderías no eximidas del impuesto, siempre que no se trate de bienes suntuarios.
• Utilidades y dividendos, en los términos del Régimen Informativo Contable Mensual para Operaciones de Cambio del BCRA, Código I03.
• Operaciones de compra de billetes y divisas en moneda extranjera para la repatriación de inversiones de portafolio de no residentes generadas en cobros en el país de utilidades y dividendos recibidos a partir del 1° de septiembre de 2019.
• La suscripción en pesos de “Bonos para la Reconstrucción de una Argentina Libre” emitidos por el BCRA o de aquellos bonos o títulos que esa institución emita en el futuro con igual finalidad, por parte de quienes los adquieran en concepto de:
  (i) pago de utilidades y dividendos
  (ii) repatriación de inversiones de portafolio de no residentes generadas en cobros en el país de utilidades y dividendos recibidos a partir del 1° de septiembre de 2019

La suscripción de bonos o títulos emitidos por el Banco Central quedará gravada, sobre el importe total de la operación, de la siguiente forma:

• A partir del 1 de febrero de 2024, a la alícuota que corresponda a la operación de importación por la que se suscriben los bonos o títulos.

La entrada Comprar una PC será más barato en Argentina: El Impuesto PAIS se reducirá un 10% para Importadores a partir del 02/09 apareció primero en PC Master Race Latinoamérica.

We don’t know how you feel when designing hardware, but we get uncomfortable at the extremes. High voltage or current, low noise figures, or extreme frequencies make us nervous.  [Orion Serup] from CrabLabs has been turning up a few of those variables and has created a fairly beefy 3-phase motor driver using GaN technology that can operate up to 80V at 70A. GaN semiconductors are a newer technology that enables greater power handling in smaller packages than seems possible, thanks to high electron mobility and thermal conductivity in the material compared to silicon.

The KiCAD schematic shows a typical high-power driver configuration, broken down into a gate pre-driver, the driver itself, and the following current and voltage sense sub-circuits. As is typical with high-power drivers, these operate in a half-bridge configuration with identical N-channel GaN transistors (specifically part EPC2361) driven by dedicated gate drivers (that’s the pre-driver bit) to feed enough current into the device to enable it to switch quickly and reliably.

The design uses the LM1025 low-side driver chip for this task, as you’d be hard-pushed to drive a GaN transistor with discrete components! You may be surprised that the half-bridge driver uses a pair of N-channel devices, not a symmetric P and N arrangement, as you might use to drive a low-power DC motor. This is simply because, at these power levels, P-channel devices are a rarity.

Why are P-channel devices rare? N-channel devices utilise electrons as the majority charge carrier, but P-channel devices utilise holes, and the mobility of holes in GaN is very low compared to that of electrons, resulting in much worse ON-resistance in a P-channel and, as a consequence, limited performance. That’s why you rarely see P-channel devices in a circuit like this.

Of course, schematic details are only part of the problem. High-power design at the PCB level also requires careful consideration. As seen from the project images, this involves heavy, thick copper traces on two or more heavily via-stitched layers to maximise copper volume and lower resistance as far as possible.  But, you can overdo this and end up with too much inductance in critical areas, quickly killing many high-power devices. Another vital area is the footprint design for the GaN device and how it connects to the rest of the circuit. Get this wrong or mess up the soldering, and you can quickly end up with a much worse performance!

We’ve seen DIY high-power controllers here a few times. Here’s an EV controller that uses discrete power modules. Another design we saw a few years ago drives IGBTs for a power output of 90kW.

The Rabbit R1 is a compact AI-powered device that aims to make it easier to interact with the technology you use every day. Equipped with a touchscreen, camera, microphone, and integrated AI assistant, it allows you to perform tasks and access services just by speaking to it. It’s designed to be a voice-first alternative to […]

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