Does the Q9300 consume less power than the Q9450?

[Globulus]

Judging from a multitude of uninformed reports, one could get the impression that a Q9450 was a rejected Xeon X3350, and a Q9300 was a rejected Q9450

My question is:

Does anyone know for sure if the Q9300 is using the same die as Q9450, albeit with half the cache disabled?

If so, does the Q9300 consume less power than the Q9450?

Looking at photographs of the die (http://images.appleinsider.com/penryn-die-070329.jpg), the cache makes up half the chip, so if half the cache has been disabled, one would imagine that it should not draw any power.

I guess it would require a test where both chips are running idle at the same frequency, but so far, I have not found any information of the sort.

Basically, what I would like to know is whether the Q9300 requires (significantly) less cooling than the Q9450.

Anyone?

 

[Andrius]

They are the same chip. But since every piece of silicone is diffrent they get binned.
Most likely the Q9300 failed the 12MB cache tests. In theory it could have been a QX9650.
At idle they should have about the same power consumption as they both run idle at 6x333MHz.

Other than that
power = capacitance * frequency * voltage * voltage
or something like that.

In other words.
Q9300 under load might run a few degrees cooler on the same cooler(heatsink).

The stock heatsink of the Q9300 is rubish.

 

[Globulus]

Ok. I am getting a Q9300 soonish. I ordered a Zalman 8700NT cooler as well.

The 8700 might have been a mistake, but I did not want a monstrous 900+ gram cooler bending my motherboard and I thought that the 8700 in any event would be better than the stock cooler.

I am hoping that I can push it to 3.0Ghz with the 8700 cooler at lowest speed, but if not, I will just run it (the cpu) at stock speed. The machine is going to be used for software development - not gaming. Silence is more important to me than performance.

 

[Andrius]

Motherboard bending with a backplate mount is not that much of an issue.

For basic multitasking (VisualStudio programming, web browsing codeproject/MSDN) you will not notice a large difference in performance between 2.5GHz and 3.0GHz (the CPU will be idle 99% of the time).

The stock Intel CPU fan is quite silent when new. It's cooling performance is rubish. My friends stock Q9300 idles around 50°C. Under load it's close to 70°C on all 4 cores. Still quite silent.

 

[Globulus]

Well, one more use I forgot to mention is playback of 720p or 1080p video. My current system (P4 Northwood@2.6Ghz, nVidia 7600GS) has no problem with .wmv files at 720p, but struggles with 720p .mkv files (in VLC Media Player). I am sure that the new Q9300 + nVidia 8500GT combo will copy nicely with that, even at stock speed, but the cpu certainly won't be idle.

The system will also be used for image and video processing, virtual instruments, and possibly 3D rendering, so yes, though it will be idle most of the time, it will also feel the pressure at other times, so I need to know that the system runs cool and rock stable, even under load.

70C under load, you say? That sounds like a lot. Are you sure it is not just one of those motherboards that cannot seem to report the correct values for the new cpus?

 

[Andrius]

720p/1080p also runs flawlessly on both 2.4/2.5 and 3.0GHz no noticable difference. CPU usage will be around 30% at stock.

The tasks you mention are quite CPU intensive, yes. Make sure you get a quality power supply to insure stability.

New chips have digital thermal sensors built in so the readout is quite accurate with the right program. 70°C is close to the thermal limit. An aftermarket cooler is a very good idea in most cases. So are extra case fans in case you have none.

 

[Globulus]

720p/1080p also runs flawlessly on both 2.4/2.5 and 3.0GHz no noticable difference. CPU usage will be around 30% at stock.

The tasks you mention are quite CPU intensive, yes. Make sure you get a quality power supply to insure stability.

New chips have digital thermal sensors built in so the readout is quite accurate with the right program. 70°C is close to the thermal limit. An aftermarket cooler is a very good idea in most cases. So are extra case fans in case you have none.

I have a Zalman ZM850-HP PSU, which is total overkill for my system, but I bought it because it was quiet and - yes - to ensure stability, no matter what I would eventually throw at it.

 

[Andrius]

I have a Zalman ZM850-HP PSU, which is total overkill for my system, but I bought it because it was quiet and - yes - to ensure stability, no matter what I would eventually throw at it.

As long as you don't throw SLI/CrossFire at it, it should be fine yes.

High end graphics already have >500W PSUs in system recommendations (GF 9800GTX, GF 9800GX2, HD 3870 X2).