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Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

xbitlabs.com

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Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#31

Post by elwin »

astrodust wrote: post #27
elwin wrote: post #23

Earlier quoted context omitted.

There are some interesting reasons for that. 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 con…

You're implying it could be done if whatever load distribution and power condition that's done outside of the chip, which consists of a lot of analog components to help manage rapid changes in power consumption, could be somehow packaged inside the chip. 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,…

> 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?

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.

Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#32

Post by coldtea »

dman wrote: post #8
twoodfin wrote: post #5

Only if you want the C6/C7 states, which are the really low power draw ones. If you're the kind of person who builds your own PC, it's unlikely you really care about saving a few watts while in sleep. At worst, you'll get Ivy Bridge-level power consumption.

On the contrary in 2013 the kind of person who builds their own PC's is the only one who likely cares about technical specs. If "good enough" is good enough for you there is very little reason to build your own box these days.

>As it appears, end-users will either have disable low-power states of Haswell or get a new power-supply units compatible with the new Intel chip.

Low power consumption is not one of the specs the PC building crowd really cares about. Especially if it means taking a performance hit.

Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#33

Post by joenathan »

MertsA wrote: post #28
kwantam wrote: post #7

Perhaps someone will helpfully design a "PSU stability dongle" comprising a 26.1 Ohm resistor (standard 1% resistor value sufficient to ensure >450mA from 12V) and a Molex connector. Make it a passthrough. 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 i…

Technically it would have to be on the same rail as the 12V CPU power connector so a Molex 8981 connector ( http://en.wikipedia.org/wiki/Molex_connector#Disk_drive_conn... ) wouldn't cut it.

Molex is a company that makes many different types of connectors, so a Molex connector would cut it.

http://www.molex.com/molex/search/keyword_select.jsp?channel...

Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#34

Post by criley »

jkldotio wrote: post #24
criley wrote: post #12

Earlier quoted context omitted.

On the contrary to your contrary: the kind of person who builds their PC is the kind who customizes how it works when they're using it . There's no automatic assumption that they also harbor green feelings and want lower power consumption for idle/sleep. 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.…

>Others are proud of their energy-destroying bit-coin mining setups. I'd be proud of my bitcoin mining setup too if it could violate the laws of thermodynamics.

I meant destruction to be synonymous with consuming, such as "Wow, I just destroyed that burger" ;)

Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#35

Post by ars »

EvilLook wrote: post #20
hga wrote: post #17

Earlier quoted context omitted.

How about the MTBF spec? 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/…

I consider it borderline negligent to use anything other than ECC RAM in any machine where you care about not corrupting your data with a flipped DRAM bit.

Except it's virtually impossible to find a CPU that supports ECC.

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).

Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#36

Post by astrodust »

elwin wrote: post #31
astrodust wrote: post #27

Earlier quoted context omitted.

You're implying it could be done if whatever load distribution and power condition that's done outside of the chip, which consists of a lot of analog components to help manage rapid changes in power consumption, could be somehow packaged inside the chip. 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,…

> 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? 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…

Ah, so the ground gets pulled up and the power driven down.

Thanks. This makes a lot more sense. I never thought Intel was doing something for no reason, but the reasoning wasn't obvious.

Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#37

Post by tolle »

ars wrote: post #35
EvilLook wrote: post #20

Earlier quoted context omitted.

I consider it borderline negligent to use anything other than ECC RAM in any machine where you care about not corrupting your data with a flipped DRAM bit.

Except it's virtually impossible to find a CPU that supports ECC. 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).

Most AMD processors support it. At least the AM3/AM3+ ones. But only ASUS seems to have support for it enabled on the motherboards.

Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#38

Post by wmf »

coldtea wrote: post #32
dman wrote: post #8

Earlier quoted context omitted.

On the contrary in 2013 the kind of person who builds their own PC's is the only one who likely cares about technical specs. If "good enough" is good enough for you there is very little reason to build your own box these days.

> As it appears, end-users will either have disable low-power states of Haswell or get a new power-supply units compatible with the new Intel chip. Low power consumption is not one of the specs the PC building crowd really cares about. Especially if it means taking a performance hit.

Except in the case of HTPCs.

Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#39

Post by jlarocco »

criley wrote: post #12
dman wrote: post #8

Earlier quoted context omitted.

On the contrary in 2013 the kind of person who builds their own PC's is the only one who likely cares about technical specs. If "good enough" is good enough for you there is very little reason to build your own box these days.

On the contrary to your contrary: the kind of person who builds their PC is the kind who customizes how it works when they're using it . There's no automatic assumption that they also harbor green feelings and want lower power consumption for idle/sleep. 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.…

On the other hand, you can't automatically assume they don't care about it at all.

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.

Re: Intel Core i “Haswell” CPUs May Require New Power Supply Units for PCs

#40

Post by AUmrysh »

jlarocco wrote: post #39
criley wrote: post #12

Earlier quoted context omitted.

On the contrary to your contrary: the kind of person who builds their PC is the kind who customizes how it works when they're using it . There's no automatic assumption that they also harbor green feelings and want lower power consumption for idle/sleep. 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.…

On the other hand, you can't automatically assume they don't care about it at all. 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.

I agree. It really depends on why someone is building the PC. Sometimes you want to optimize the gaming performance, or video editing performance, or the file transfer speed and lower latency for a NAS box, or other times you're looking to optimize video playback, low power consumption, and low noise on an HTPC. All of those could be built by ones self, and each will usually require certain choices and trade-offs to achieve the desired goals.
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