Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs
xbitlabs.com
xbitlabs.com
Of course, it'll have to be a >5W resistor, but that's what I like to call an opportunity to excel: just more room to add some rakish heat sink fins. You could even spend some of your power wasting budget on LEDs instead, but obviously we'll have to charge more for that model. The margins, you see.
http://www.molex.com/molex/search/keyword_select.jsp?channel...
Hell, many are proud of their beefy 1kW+ power supplies and the ridiculous power load they draw.
Others are proud of their energy-destroying bit-coin mining setups.
You certainly can't assume that the home builder cares at all about power consumption.
I'd be proud of my bitcoin mining setup too if it could violate the laws of thermodynamics.
I build most of my desktops, and I certainly want to reduce power usage when I'm not using them. Enough so that I'd pay for a power supply that supports the lower power states.
Not everybody who builds their own PC is doing so to make a ridiculously over powered system.
My actual, active goal is to build a quad core machine with 16 gibibytes of RAM that can draw < 100W at full bore.
IOW, you can't assume that those of us who build our machines are all, "Look how big my electric bill is!" wastrels, either.
TDP is all about cooling capacity and PSU capabilities. If you're worried about saving energy, get the processor that will run at the highest speed while computing so that it can get back into power-saving mode sooner. And you can always under-clock the standard desktop CPUs if you really want to - a 3770 can be configured to behave pretty much like a 3770T by tweaking the base and Turbo multipliers.
I exclusively use server or workstation/server class motherboards from Supermicro or Tyan not just for myself but also for my parents, so I can then largely ignore the hardware for 5+ years plus not worry about non-reproducible errors from radiation flipping a DRAM bit. I've done this since 1995-6 and never had one fail in the field except through an act of God (http://en.wikipedia.org/wiki/2011_Joplin_tornado).
For this purpose, decreasing stress from thermal cycling is good.
(Yeah, they're grossly overpowered for what my parents do, but since I'm not including my labor in the cost they really don't cost that much.)
I've used ECC in every one of my machines for the last decade or so - except for the very last once since it's was impossible to get without spending a crazy amount of money (xeon processor).
And as mentioned elsewhere, AMD's consumer CPUs support ECC if the motherboard enables it.
Low power consumption is not one of the specs the PC building crowd really cares about. Especially if it means taking a performance hit.
Errr, is not like many end users update their desktop PC with new CPUs anyway.
And those very few that do, they also buy a new motherboard, so to get a new power supply is nothing significant in comparison.
Is it somehow not practical to have several bigger pins for power that can handle more current than to have literally hundreds of pins dedicated to power? A surprising percentage of the pins on a modern Intel chip do nothing more than power the chip. The traditional pair of +Vcc and GND pins just can't cut it, apparently, and no wonder with some chips drawing over 100W of power.
Not too long ago video cards started taking a direct feed from the PSU rather than relying on the PCI or PCIe bus. It's surprising the same thing hasn't happened to high-power integrated circuits.
Oh also, if you want fewer power pins, get ready for more heat and way more expensive CPUs. The pins are placed to be as cost effective and efficient as possible to power the individual chip modules (many of which will operate at different voltages). Also, it's way cheaper to convert power on the motherboard than within an already incredibly constrained CPU package.
Edit: "vast majority" as far as power and other connections to the board go, the transistors create way more heat than the interconnects.
And (I think) the copper circuits are so close that quantum leaps can occur -- electrons can just decide to jump from one piece of copper to another, straight through silicon or anything else, simply because the copper is so close. This means a VCC line can be giving charge to an unpowered neighboring circuit or memory cell without magnetically affecting it.
When a lot of transistors in an integrated circuit all switch at the same time, it can cause the chip's power and ground voltage levels to shift, relative to the circuit board's power and ground levels. The size of the difference depends on the inductance between the chip and board, i.e. the inductance of the chip's power and ground pins. Inductance can be minimized by connecting a lot of inductors in parallel. Lots of small pins are better than a few big ones.
If the inductance is too high and the chip's power voltage falls below its ground voltage, this will randomize every storage element on the chip. The rule of thumb is that a third of the pins need to be power or ground.
So, in rough terms, the internals of a large-scale chip are not one big integrated circuit, but a large number of smaller modules that are massively interconnected, then?
That rule of thumb seems to apply to only a particular class of chips. Wouldn't the number of pins be somehow proportional to the power draw, as at higher currents induction would become a more severe problem? It's just usually the case that more power-hungry chips have more pins, as the 2011 socket is for Intel's flagship CPUs, the 1155 ones more commodity-oriented.
With the power voltage dropping below ground, that unless you had a floating ground, that'd be implying reverse flow of current, negative voltage, right? Or are you talking about a non-zero voltage ground? I'm not sure what the presumption is in real-world CPU design.
I think it depends on the chip's speed. The problem is with rapid changes in current. Of course, higher currents can also have higher fluctuations.
> With the power voltage dropping below ground, that unless you had a floating ground, that'd be implying reverse flow of current, negative voltage, right? Or are you talking about a non-zero voltage ground?
Suppose the board's ground rail is 0 V and the power rail is at 12 V. The chip's ground voltage might bounce up to 9 and its power down to 8. It does cause reverse currents and other bad effects.
Thanks. This makes a lot more sense. I never thought Intel was doing something for no reason, but the reasoning wasn't obvious.
Second, CPUs have a dedicated 12V rail on the MB since quite some time. It's plugged in right near the voltage regulators of the CPU.
Third, a GPU die also has multiple power rails and distribution over the die as CPUs. Given the insane power requirements and transistor count, they likely have even more. The same is true for other power hungry ICs, for example high-speed DSPs, FPGAs, image sensors and so on.
Fourth, PCI/PCIe can't carry hundredths of watts, it would not be cost effective to kit out PCs with heavy duty connectors and thick main board traces just because one or two slots may one day be used for a space heater. Thus another dedicated rail from the PSU.
... because the motherboard manufacturers can't figure out how to stuff a 240 ohm resistor across the 12v rail?
Edit to be fair: if the power savings from going from the legacy suspend to the Haswell states is less than 600mW, then this isn't worth it and disabling the Haswell states is the right solution. In my experience though, PC motherboards almost never idle at less than 3-5W.
To test the PSU works at 0.5A would end up shutting down the computer if the PSU didn't work at 0.05A... exactly what happens today. Unfortunately, at that point it is too late to tell the user "your PSU is old" or to quickly connect a resistor across the +12v rails to work around the problem.
As an experiment, find an old PSU and plug it into the wall (nothing connected to the power output connectors). It won't power on. If you connect a 2 ohm 10W resistor (or two 1 ohm 5W resistors in series) into the "hard drive" Molex connector +12v (yellow) to ground (black), it should start up and be happy.
Disclaimers:
1) The resistor will become quite warm quite quickly (6W), watch your fingers.
2) If you damage something, it is a learning experience, not my fault.
https://www.google.de/search?q=atx+power+supply+pinout&c...
The most likely outcome though is that the supply will just power on and idle without any load. Rapid transients on the rails (say from 100W to ~0W) might cause the over voltage crowbar to trip, though.