Bulldozer CPU's - Page 3

zero_velocity · 13th April 2012, 5:26 PM

Got 2x 6970's CF with a 955BE @ 3.5GHz NB @ 2.6Ghz (Not a huge overclock I know) and I run everything maxed out and always get a solid average 60-80 fps on all my games

mAJORD · 13th April 2012, 6:03 PM

It's not just the cost of power, it's heat

More power = More heat = better cooling required (noisier, more expensive). This is important to many.

Now, fair enough if it's a minor difference (like was the case for many AMD chips before ) but it's not in this case.. the perf/watt is wildly different between BD and SB

it's not so bad in real life scenaro's because CPU use is sporatic, so if you have good Idle power consumption, it evens itself out a bit.

Back in the Athlon X2 vs Core 2 days, AMD platforms had better idle, but higher load power draw, This is because Cool and quiet had a lower minimum clockspeed, and also the Intel chipsets of the day were built on an old process, and had to run a high speed FSB to compensate for the lack of memory controller on board.

this meant that whilst people harped on how the conroe architecture had lower power consumption (load) , in reality, for many people there'd either be no difference, or perhaps even an advantage for the AMD systems if you actually looked at power draw over say a week, with your PC idle or near idle for ~80% of the time.

Now, BD has pretty much the same low idle power draw as Intel, but significantly higher load draw.. At no time does actually hold an advantage, so it's still going to come out worse on a weekly avg.

We'll see how Piledriver goes, especially trinity which looks semi promising for lower end systems.

Ethan W · 13th April 2012, 6:47 PM

Quote:

Originally Posted by mAJORD

It's not just the cost of power, it's heat

More power = More heat = better cooling required (noisier, more expensive). This is important to many.

It's not just how the heat affects the CPU - even if you have a great heatsink pumping, that heat is going somewhere. In summer, you can really feel the heat build up in your computer room, until you might need to run airconditioning to keep the ambient temp down (in the room, not the PC). Now THAT can make a big difference on the power bill.

I hate the room heating up, so I choose to run my Phenom at 3.8GHz/1.275V or even stock, rather than 4GHz/1.5V it can do, because the ambient temp is that much lower.

Numbers: a room with 100 sq ft area is recommended to have 900W heating to keep it warm in winter. Just think, a heavily OCed, single-GPU computer could be pumping out half of that. If you have a small room in summer, that's going to be a little to warm for comfort.

Madengineer · 13th April 2012, 7:01 PM

Quote:

Originally Posted by Ethan W

It's not just how the heat affects the CPU - even if you have a great heatsink pumping, that heat is going somewhere. In summer, you can really feel the heat build up in your computer room, until you might need to run airconditioning to keep the ambient temp down (in the room, not the PC). Now THAT can make a big difference on the power bill.

I hate the room heating up, so I choose to run my Phenom at 3.8GHz/1.275V or even stock, rather than 4GHz/1.5V it can do, because the ambient temp is that much lower.

Numbers: a room with 100 sq ft area is recommended to have 900W heating to keep it warm in winter. Just think, a heavily OCed, single-GPU computer could be pumping out half of that. If you have a small room in summer, that's going to be a little to warm for comfort.

This man speaks the truth!

My PC heats up my room quite well in winter even at stock. you can tell the difference between my room and the living area.

NNNG · 13th April 2012, 7:13 PM

My room heats up even when the computer is at idle with the screens turned off.

Lucky I don't pay for the power, if I did I likely would have bought an AMD graphics card (this was before current gen cards), a P45 motherboard, and a much more efficient power supply. I would also run at a much lower OC (like 3.0ghz). Northbridge has a TDP of 40 watts. I run it at 1750 FSB. CPU is what? 175 watts. So CPU + NB on my system is like >215 watts full load... whereas Sandy Bridge will get 40% more performance with a power consumption of like 95 watts... Oh how far we have come!

Also putting inductors in the chip to offset capacitance or whatever to reduce impedance to allow a higher clock sounds like a great idea. Piledriver will use this. Wonder how much better it will be over BD. Since Ivy Bridge doesn't clock higher than Sandy Bridge, wonder if Piledriver could match Ivy Bridge when OC'd in terms of performance.... Anyway, I'm getting way off-topic.

dirtyd · 13th April 2012, 9:08 PM

Quote:

Originally Posted by NNNG

Also putting inductors in the chip to offset capacitance or whatever to reduce impedance to allow a higher clock sounds like a great idea. Piledriver will use this. Wonder how much better it will be over BD. Since Ivy Bridge doesn't clock higher than Sandy Bridge, wonder if Piledriver could match Ivy Bridge when OC'd in terms of performance.... Anyway, I'm getting way off-topic.

Yeah but the problem with using resonance is that it's entirely frequency dependent. Change the frequency and you have to change inductance or capacitance, so I don't think we'll be overclocking Trinity. Vishera (the desktop Piledriver) might avoid it altogether I think.

NNNG · 13th April 2012, 10:25 PM

Quote:

Yeah but the problem with using resonance is that it's entirely frequency dependent. Change the frequency and you have to change inductance or capacitance, so I don't think we'll be overclocking Trinity. Vishera (the desktop Piledriver) might avoid it altogether I think.

Does it have to be at resonance?

dirtyd · 13th April 2012, 11:50 PM

Well there's nothing to say it does, but I reckon the power draw will get ugly quickly considering the savings from resonance will be offset by more aggressive clocks to boost the performance within a particular TDP. There will also probably no downclocking to save power as they can just shut off logic and leave the clock running, so if you've overclocked your idle power savings will vanish.

Signal issues may arise at higher clocks but that's out of my technical grasp unfortunately

Also this is all highly speculative on my part, for all I know AMD may have invented a magical fairy-dust variable inductor

zero_velocity · 14th April 2012, 6:59 AM

Quote:

Originally Posted by dirtyd

Also this is all highly speculative on my part, for all I know AMD may have invented a magical fairy-dust variable inductor

Variable inductors do exist - they use a tap changing mechanism. Power transformers use this tap changing method quite extensively as when load is applied to high voltage PT's, the voltage can drop, so they up the turns ratio.

The best way I can see of doing this electronically would be to somehow have a switching mechanism as a tap changer is a mechanical operation and fairly impractical for a mobo.

Something along the lines of a really large inductor divided up into small portions through the use of transistors that can shut off sections, and much the same technique for the capacitanc e side of things.

Although this will all require a lot more components than I deem it worth :/

mAJORD · 14th April 2012, 11:06 AM

the inductance is tiny (nH range) and are on the die itself - made from the metal layers. The Capacitance is already there in the form of the clock mesh itself.

The info's a bit vague though, so hard to say the implications of running outside the resonant frequency. How welse would they provide higher / lower clocked SKU's?

13th April 2012, 7:13 PM	#35
NNNG Member Join Date: Sep 2009 Location: SE Melbourne. Posts: 1,288	My room heats up even when the computer is at idle with the screens turned off. Lucky I don't pay for the power, if I did I likely would have bought an AMD graphics card (this was before current gen cards), a P45 motherboard, and a much more efficient power supply. I would also run at a much lower OC (like 3.0ghz). Northbridge has a TDP of 40 watts. I run it at 1750 FSB. CPU is what? 175 watts. So CPU + NB on my system is like >215 watts full load... whereas Sandy Bridge will get 40% more performance with a power consumption of like 95 watts... Oh how far we have come! Also putting inductors in the chip to offset capacitance or whatever to reduce impedance to allow a higher clock sounds like a great idea. Piledriver will use this. Wonder how much better it will be over BD. Since Ivy Bridge doesn't clock higher than Sandy Bridge, wonder if Piledriver could match Ivy Bridge when OC'd in terms of performance.... Anyway, I'm getting way off-topic. __________________ \| i5-3570K @ 4.4 \| Z77X-UD3H \| 16GB DDR3-1866 \| GTX 570 OC \| Corsair HX620 \| Antec P280 \| 160GB X18-M G2 \| Filco TKL \| Crossover 27Q (2560x1440, IPS) \| + $900 of trades. Last edited by NNNG; 13th April 2012 at 7:50 PM.

13th April 2012, 11:50 PM	#38
dirtyd Member Join Date: Jan 2006 Location: 127.0.0.1 Posts: 3,681	Well there's nothing to say it does, but I reckon the power draw will get ugly quickly considering the savings from resonance will be offset by more aggressive clocks to boost the performance within a particular TDP. There will also probably no downclocking to save power as they can just shut off logic and leave the clock running, so if you've overclocked your idle power savings will vanish. Signal issues may arise at higher clocks but that's out of my technical grasp unfortunately Also this is all highly speculative on my part, for all I know AMD may have invented a magical fairy-dust variable inductor __________________ "It is worthy of remark that a belief constantly inculcated during the early years of life, whilst the brain is impressible, appears to acquire almost the nature of an instinct; and the very essence of an instinct is that it is followed independently of reason." - Charles Darwin \| trustworthy traders

13th April 2012, 6:03 PM	#32
mAJORD Member Join Date: Jun 2002 Location: Griffin , Brisbane Posts: 6,725	It's not just the cost of power, it's heat More power = More heat = better cooling required (noisier, more expensive). This is important to many. Now, fair enough if it's a minor difference (like was the case for many AMD chips before ) but it's not in this case.. the perf/watt is wildly different between BD and SB it's not so bad in real life scenaro's because CPU use is sporatic, so if you have good Idle power consumption, it evens itself out a bit. Back in the Athlon X2 vs Core 2 days, AMD platforms had better idle, but higher load power draw, This is because Cool and quiet had a lower minimum clockspeed, and also the Intel chipsets of the day were built on an old process, and had to run a high speed FSB to compensate for the lack of memory controller on board. this meant that whilst people harped on how the conroe architecture had lower power consumption (load) , in reality, for many people there'd either be no difference, or perhaps even an advantage for the AMD systems if you actually looked at power draw over say a week, with your PC idle or near idle for ~80% of the time. Now, BD has pretty much the same low idle power draw as Intel, but significantly higher load draw.. At no time does actually hold an advantage, so it's still going to come out worse on a weekly avg. We'll see how Piledriver goes, especially trinity which looks semi promising for lower end systems.

14th April 2012, 11:06 AM	#40
mAJORD Member Join Date: Jun 2002 Location: Griffin , Brisbane Posts: 6,725	the inductance is tiny (nH range) and are on the die itself - made from the metal layers. The Capacitance is already there in the form of the clock mesh itself. The info's a bit vague though, so hard to say the implications of running outside the resonant frequency. How welse would they provide higher / lower clocked SKU's?