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A birthday present from Broadcom

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Re: A birthday present from Broadcom

#131

Post by wtallis »

csense wrote: post #124
stingraycharles wrote: post #32

Earlier quoted context omitted.

This is confirmed by the recent move of AMD towards extremely hot GPUs. You already see that in the most recent 290x, but they're talking about making hardware that is comfortable running at >100C. I'm not sure how relevant that is with regards to performance per watt, but I do know that heat is one of the most expensive (by-)products of electricity.

Isn't there some theorem of thermodynamics that says your device gets more efficient as the temperature difference between the hot and cold parts of the device increases? AFAIK the only reasons devices aren't run at arbitrarily high temperatures is that material properties change unfavorably, or you risk fires.

The efficiency thing is more about heat engines. When we're just dissipating heat, the relevant relationship is that the rate of heat transfer is proportional to the temperature difference. This is why a hot object that isn't producing heat will cool exponentially. In the case of a steady-state source of heat, the temperature difference will be inversely proportional to the thermal conductivity of the connection between hot and cold reservoirs. Heatsinks and fans are used to increase that thermal conductivity so that the temperature difference stays small enough that the absolute temperature is safe. If you can double the tolerable temperature difference, then you can cut your fan speeds by more than half, or even get by with passive convection.

Or, approaching things differently, if you're only going to keep your graphics card for two or three years, there's no reason to let the fans spin up to an audible level until the chip reaches at least 80 degrees C.

Addressing a common misconception: fan speed/noise is not directly related to how much the graphics card is heating up the room by. Whether you run the fans at full tilt or you let the chip almost melt, the heat output will depend only on the workload.

Re: A birthday present from Broadcom

#132

Post by ardacinar »

GFK_of_xmaspast wrote: post #102
bdamm wrote: post #94

Earlier quoted context omitted.

git is overkill for facilities with small groups working in a common area (not hard to imagine if you're in the hardware biz) and all the engineers are used to cvs command syntax..

The best VCS is the one you use.

unless it's CVS, or god forbid, Visual SourceSafe.

Re: A birthday present from Broadcom

#133

Post by zxexz »

sneak wrote: post #92
ansible wrote: post #84

Earlier quoted context omitted.

Whatever RasPi is, the fact remains that they're selling a relatively open platform at price near production costs. And that platform just got significantly more open. And they are now offering a bounty for the creation (refinement, really) of more free software. Which will benefit the entire community surrounding the RasPi. So that is good. Even if they were offering $10 USD, there might be someone who'll take up th…

"Relatively open" in the way that your mother was "relatively pregnant" when you were born?

Are you suggesting he's a premie?

Re: A birthday present from Broadcom

#134

Post by akiselev »

zanny wrote: post #114
akiselev wrote: post #68

Earlier quoted context omitted.

Looking at the long term future of the market, Broadcom's move isn't surprising at all. Broadcom (and Qualcomm for that matter) is feeling a lot of pressure from Intel and NVidia, both of whom have a lot of new stuff that are scaring competitors (which is fucking great for us). They're scared not from just a technological or capital/market perspective, but also from a community exposure one. They're both firing on al…

> NVIDIA (and maybe Intel) Intel has a huge workforce dedicated to open source. They fund huge chunks of kernel, Wayland, X and Mesa development, and I'm sure they have engineers on projects throughout the foss stack. Yeah, their hardware is pretty systemically evil patent drivel black box nonsense, and their chipsets are some of the most obscure bullshit ever, but everything past the firmware they do a good job on.…

Thank you for clarifying. I wrote "maybe Intel" because I've never looked at their reputation for open source.

Re: A birthday present from Broadcom

#135

Post by akiselev »

Taniwha wrote: post #129
akiselev wrote: post #55

Earlier quoted context omitted.

This is almost a universal problem with firmware and chip engineers, who are generally older and more experienced, and thus apparently can't be taught new tricks. There are also issues with bureaucracies in each and every semiconductor company (which are on average decades old) so firmware is usually hot potatoed around by management and ends up lighting the customers' projects on fire almost every damn time. I don't…

akislev: I think you paint with too broad a brush - I've worked as a chip designer, embedded systems programmer, kernel hack - it really depends on the team - also most chip teams I've worked with have been relatively young (most in their 20s)- most big silicon projects depend on good version control software because you are doing continual integrations and practice tapeouts through the last half of a project - you m…

Ooops yeah I chose the wrong words and painted way too broad. I meant version control as far as the firmware libraries and public facing code. I can't imagine going from FPGA to silicon synthesis is even possible without extremely tight version control of some sort or another (I think they used to use basic transperencies for comparing masks)

I stand corrected as far as the average age of employees but every time I have interfaced with any level of a silicon company the average age distribution has been skewed pretty high.

Re: A birthday present from Broadcom

#136

Post by tryp »

csense wrote: post #124
stingraycharles wrote: post #32

Earlier quoted context omitted.

This is confirmed by the recent move of AMD towards extremely hot GPUs. You already see that in the most recent 290x, but they're talking about making hardware that is comfortable running at >100C. I'm not sure how relevant that is with regards to performance per watt, but I do know that heat is one of the most expensive (by-)products of electricity.

Isn't there some theorem of thermodynamics that says your device gets more efficient as the temperature difference between the hot and cold parts of the device increases? AFAIK the only reasons devices aren't run at arbitrarily high temperatures is that material properties change unfavorably, or you risk fires.

The thermodynamics you are remembering mostly refers to Carnot engines which convert temperature differences to work.

Re: A birthday present from Broadcom

#137

Post by LukeShu »

jxf wrote: post #72
petermonsson wrote: post #69

Earlier quoted context omitted.

The original article states that the code is licensed under a 3-clause BSD license. The 3-clause BSD license permits redistribution: https://en.wikipedia.org/wiki/BSD_licenses

That's pretty much what I just said. "In this case it's okay as long as you reproduce the license in any redistributions (e.g. hosting it on GitHub)."

So how is that "not what 'open source' means"?

Re: A birthday present from Broadcom

#138

Post by srcmap »

jxf wrote: post #21

If you want to go straight to the horse's mouth and just start hacking (this is Hacker News, after all!), the Broadcom downloads are here: * BCM21553 VideoCore IV graphics driver source: http://www.broadcom.com/docs/support/videocore/Brcm_Android_... * BCM21553 VideoCore IV documentation: http://www.broadcom.com/docs/support/videocore/VideoCoreIV-A...

I love raspberrypi!

I created the srcmap index of raspberrypi_userland src tree here:

http://www.srcmap.org/s/sl.htm/p=raspberrypi_userland#c=P&d=...

Hope you guys find it useful.

Re: A birthday present from Broadcom

#139

Post by bigiain »

GFK_of_xmaspast wrote: post #102
bdamm wrote: post #94

Earlier quoted context omitted.

git is overkill for facilities with small groups working in a common area (not hard to imagine if you're in the hardware biz) and all the engineers are used to cvs command syntax..

The best VCS is the one you use.

There _are_ differences, but yeah - you're arguing about the ranking of the 99.91% - 99.95% better solutions compared to no version control. (Seriously - even CVS and SourceSafe are 99.9% closer to "perfect" than doing nothing)

Re: A birthday present from Broadcom

#140

Post by stbtrax »

aswanson wrote: post #101

Wow. In due time these guys might start actually releasing datasheets to developers who, you know, need to know the register set and API to like, make their chips work. I don't know why the hell these idiots treat their firmware APIs with Manhattan-project style secrecy, but I would highly advise against designing a new product with a broadcom chipset. They are totally asinine.

I don't think you can even start a new product with a broadcom soc if you're not already a huge player.
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