Power Consumption

The beauty of a console is that the specs never change, so while AMD, Intel and NVIDIA have to try to add new features or increase clock speeds with each die shrink, Microsoft gets to sit back and reap the benefits of cooler running hardware that's cheaper to manufacture. The move from Xenon to Falcon resulted in a pretty significant reduction in power consumption; under full load a Falcon Xbox 360 drew less power than a Xenon unit at idle.

The Falcon to Jasper transition isn't quite as dramatic unfortunately. I ran five power tests, I looked at power consumption at the NXE dashboard at idle, power consumption at the main menu of Rockband 2, Halo 3 and Gears of War 2, and finally if you don't own any of these games but want a comparison point I looked at power consumption of the Xbox 360 while running the BioShock demo (at the very start of the demo when you find yourself in the water surrounded by fire). Power consumption during actual gameplay doesn't go up much, if at all, compared to the start screens for these games - the main menu screens are all rendered in 3D and are apparently just as stressful as the games themselves, plus they're a very consistent way of measuring power consumption.

I used a Watts-Up meter which the Xbox 360 plugged into, so what we're looking at here is total system power consumption.

Xbox 360 Revision System Off Idle Halo 3 Rockband 2 Gears of War 2 BioShock Demo
Xenon 2.3W 155.7W 177.8W 167.7W 177.1W 172W
Falcon 2.8W 101.4W 121.2W 112.8W 121.5W 115.5W
Jasper 2.0W 93.7W 105.9W 101.0W 105.9W 98.1W

 

Overall you're looking at a 12% reduction in total system power under load and under 8% at idle, definitely not the ~30 - 35% drop we saw with the Xenon to Falcon transition, but not insignificant either. Remember that the smaller your transistors get, the more leakage current becomes a problem; while your transistors use less power, they also tend to use more power when they are in a logical off state than they should. There have also been a number of advancements in architecting for low power designs over the past couple of years that Microsoft hasn't taken advantage of as they would require a redesign of the 360's CPU/GPU. Microsoft is in full blown cost savings mode with the Xbox 360, the only things that will be done to that console before it dies are things to improve the Xbox division's bottom line.

Final Words

There you have it. Jasper is out and now we play the waiting game to see if the dreaded RRoD is finally solved with the latest batch of hardware changes. Even if it's not, if you are buying an Xbox 360 today you might as well opt for the cooler running, newly redesigned Jasper model rather than the year-old Falcon. Why pay the same amount for old hardware, it's just not the AnandTech way.

And once again, to those of you with Jaspers: congrats, after 3 years you may have just bought an Xbox 360 that won't die.

Jasper Dissection
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  • strikeback03 - Wednesday, December 10, 2008 - link

    In the US we would say the number 12.1 as "Twelve point one". In places where comma and period usage are switched, how would 12,1 be spoken?
  • Spoelie - Thursday, December 11, 2008 - link

    12,1
    "twaalf komma een"
    just as you say "point", we say "comma"
  • strikeback03 - Thursday, December 11, 2008 - link

    Interesting, thanks!
  • Spivonious - Wednesday, December 10, 2008 - link

    Not European, but I believe it's "12 mark 1" or still "12 point 1" (i.e. in German it's 12 punkt 1, which translates to 12 point 1".
  • geogaddi - Wednesday, December 10, 2008 - link

    No - Krauts write "12,1" and say "zwoelf komma eins".

    Now comes the time to dance. Dieter, touch my monkey...
  • dasyentist - Wednesday, December 10, 2008 - link

    ''The Xbox 360 had a bit more graphics power than a Radeon X800 XT''

    Maybe i'm wrong but from the spec ive read it look more like the core of a x1800/x1900...
  • JarredWalton - Wednesday, December 10, 2008 - link

    The Xenos GPU is somewhere in between X800 and X1800. It has more in the way of X1800 hardware, but performance is a lot more like X800 I believe. Neither the Xbox 360 nor the PS3 launched with graphics performance that could match - let alone surpass - that of the then-current top PC GPUs (i.e. X1800 and 7800 GTX). But, there is something to be said for having a static hardware to target when making games.
  • bill3 - Thursday, December 11, 2008 - link

    I was going to comment on this glaring innacuracy in the article as well! See I'm not the only one who spotted it.

    Xenos doesnt match well to any specific ATI PC hardware of the time, being custom, but I feel fully confident in declaring it a good deal more powerful, in fact a generation ahead, of X800XT!

    The simplest way to deduce this is to compare to PS3. The RSX in PS3 is simply an 500 mhz 7800GTX with a 128 bit memory bus and a few other minor modifications (such as larger texture caches so it can handle the larger latency from PS3's XDR memory pool). The 128bit bus is not a huge handicap for many reasons. (low 720P rendering resolution, the fact RSX can texture from XDR as well as GDDR for more BW, etc etc).

    Now 360 outputs roughly the same level of graphics as PS3 overall (while a few PS3 exclusives seem to look slightly better, OTOH most multiplatform games look/run better on the 360). So it's a necessity to assume Xenos is at least roughly as powerful as 7800GTX. Does X800XT fit that bill? No. In fact the 7800GTX and it's same base specced but higher clocked brother the 7900GTX, traded blows against the ATI X1800 and X1900 cards of the time. So it's much more reasonable to place the Xenos with the X1800/1900 class ATI cards. I believe tape out times would also support that. I believe Xenos taped out in the same time frame (late 04) as G70/R520.

    You can also derive that Xenox>X800XT from more complex maneuvers such as execution resources (and probably die size as well, though I dont have that info). Xenos has 48 shader ALU's. Comparable to the 7800GTX which has 24 pipes, with 2 alu's each, for 48 (though it would also contain 6-8 vertex shader ALU's). And X800XT would have 16 pipes X2 ALU's =32 (plus 8? vertex shader ALU's). Now there are all sorts of caveats in comparing ALU's across different parts (if anything Xenos is probably a lot more efficient in utilizing it's more plentiful ALU's over X800XT, due to it's unified shading abilities, and it's ALUs can crunch an extra component as well I believe making the difference even greater), but nonetheless it probably tells us something.

    Heck, Xenos even has more raw shader resources than X1800XT. X1800 had only 32 shader ALU's as well, albeit higher clocks. Xenos is probably somewhere between X1800 and X1900 if you ask me, right in that class.

    Another evidence of this is the games, I'm not familiar with Gears of War PC benchmarks, but I bet even at 720P a X800XT would be crushed by the game, let alone Gears 2 (even allowing for the greater optimization in consoles doesnt go far enough to negate this point imo). I also dont believe games that look as great as Rage, Resident Evil 5, etc would run on an X800XT.
  • Anand Lal Shimpi - Thursday, December 11, 2008 - link

    The Xenos GPU should have fallen in between the R420 and R520 in terms of performance, remember that Xenos was ATI's first unified shader architecture GPU so direct comparisons between it and the non-unified ATI architectures of the time aren't exactly the easiest to make.

    We originally proposed that the Xenos GPU would perform similar to a 24-pipe R420, but you're correct in that it should be closer to the X1800 in performance. I will update the article to reflect that its performance falls in between both R420/520 but is closer to the 520.

    Remember that one major advantage Xenos has is its 10MB eDRAM, which definitely helps in the effective bandwidth department - making rendering with AA at 720p much more possible than other high end PC architectures available at the time.

    Even if you make the 7800 GTX comparison, we're still around 4x the speed of that with high end PC graphics today. G80 was 2x G70, and GT200 is 2x G80. By the end of next year we'll hopefully have something that is 2x GT200.

    -A
  • john-ZX10R - Tuesday, April 20, 2010 - link

    so my elight got the one red light?? 16v. GPU failure ..i went on a search to the game spots and get me my elight 12 1a unit much quieter and power brick is smaller seems good noticed buy touching the top it was a lot cooler after 10 hrs of games and netflix.but seems like the disc tray is a little sloppy when it ejects and goes back in, but i can live with it its the least of my worries i just don't want to get the red ring again i have had if for 2 days and seems to be running good so far i bought a glass pedestal that keeps it about 4 feet off the ground and allows the needed air flow i used the inter cooler on my old one and never had any issues just loud i didn't put it on my new unit as people seem to think it robs power and makes it run hotter due to power usage?? nyko 3 fan system i used to use the usb ports for charging my wireless mic and cell but not with my new one I'm going to try to keep the power usage to just what the xbox needs only.nothing more well that's my 2 cents..Sarasota Florida..

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