The 140W TDP: Is Phenom the new NetBurst?

The Phenom X4 9950 Black Edition is now AMD's hottest microprocessor, carrying a 140W TDP up from 125W of the 9850 and retail 9750. The 15W bump in TDP is all for a meager 4% increase in clock frequency. The question is: does this translate into a significantly higher increase in system power consumption?

  Idle Load (Cinebench XCPU) Vcc
AMD Phenom X4 9950 (140W TDP) 188W 279W 1.312V
AMD Phenom X4 9850 (125W TDP) 204W 297W 1.312V

 

Surprisingly enough, our 9950 sample actually used less power than our 9850. We first checked to see if they both ran on the same VID and indeed they did: 1.312V for both.

There is some power variation between CPUs, even at the same voltage, so you should definitely not assume that the 140W TDP immediately insinuates a significantly higher power draw. At the same time, AMD didn't up the rating for no reason, and it's quite possible that on average the 140W TDP processors will consume noticeably more power than their 125W counterparts.

Overclocking or Overcooking? The Test
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  • Gikaseixas - Wednesday, July 2, 2008 - link

    Other sites tested it already and could hit 3.2 - 3.6 speeds. Hopefully Anandtech will be able to overclock a Phenom to it's limits this time around.
  • Googer - Wednesday, July 2, 2008 - link

    Missing from the benchmarks is the Intel Core 2 Quad Q9550 Yorkfield 2.83GHz 12MB. How would this chip stack up against all others tested?

    http://www.newegg.com/Product/Product.aspx?Item=N8...">http://www.newegg.com/Product/Product.aspx?Item=N8...
  • RamarC - Wednesday, July 2, 2008 - link

    the q9550 isn't in the same price range as the other processors so that's why it wasn't included. as for performance, either subtract or add 10% to the q9450's figures.
  • DanD85 - Wednesday, July 2, 2008 - link

    Are you absolutely sure about that? As hothardware thinks differently:
    "By altering its multiplier and increasing the CPU voltage to 1.45v, we were able to take our Phenom X4 9950 to an respectable 3.1GHz using nothing but a stock AMD PIB cooler. Higher frequencies were possible, but we couldn't keep the system 100% stable, so we backed things down to 3.1GHz. While running at that speed, we re-ran some tests and also monitored core temperatures and found that the chip never broke the 60ºC mark, and hovered around 58ºC under load - at least according to AMD's Overdrive software. That is one heck of an overclock and relatively cool temperatures for a Phenom in our opinion. If the majority of chips have the same amount of headroom as ours, we suspect the 9950 Black Edition will be appealing to AMD CPU enthusiasts looking for the best the company has to offer."
    http://www.hothardware.com/Articles/AMD_Phenom_X4_...">http://www.hothardware.com/Articles/AMD...nom_X4_9...
  • KaarlisK - Wednesday, July 2, 2008 - link

    Maybe by setting affinity for Photoshop's threads to a certain core, it would be possible to verify whether Vista's thread management is part of the cause?
  • Zoomer - Wednesday, July 2, 2008 - link

    I know its a novel concept, but what about running some benches in XP to see if it's another Vista issue?
  • Rhoxed - Wednesday, July 2, 2008 - link

    Increasing the NB core (IMC) clock (in Phenom it runs async from the Core Speed unlike Athlon which is Sync) drops latencies (especially L3) and increases memory performance/throughput, which in turn improves system performance. The Phenom starts to come to life when you hit a 2.6GHz core speed with a NB core clock at 2200MHz+. Depending on the application and CPU, increasing NB core speeds (getting up to 2200MHz+) can result in performance differences from 3%~12% in most cases.

    Upping my NB/HT to 2400MHz over the stock 2000 at the same clockspeed (2800) i net a 15%~ increase (on a 9850BE)
  • RamarC - Tuesday, July 1, 2008 - link

    i'm a developer and want to upgrade my win2k3/ss2k5 server to a quad core. since it currently has a 3.4ghz p4d, a phenom 9x50 would be a big step-up (even though i don't have any performance issues). but the p4d has been very reliable and i don't want to have to deal with flaky hardware issues when i'm pushing code out the door. should i just bite the bullet and shell out the extra cash for a p45+q9450?
  • Calin - Wednesday, July 2, 2008 - link

    I have an AMD based PC at home, and I look forward to another AMD-based pc (780G and Phenom X3 or X4).
    These being said, I think for a server you really really should go for an Intel configuration. Also, at 3.4 GHz a P4D probably is one hell of a power draw.
    Compared to your current server, and based on what I think you need, I don't think a quad core would help you - a dual core would probably be enough, and Intel has those aplenty.
  • Zoomer - Wednesday, July 2, 2008 - link

    From the article, it seems like sticking to the cheaper, sub 100W TDP cpus and not overclocking is the way to go.

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