Multitasking Performance

As we discovered in the first article, multitasking performance requires a slightly different approach to benchmarking methodology.  While for single application performance in which we test with a system that's in a very clean state with nothing but the benchmark and drivers loaded, for our multitasking tests, we have the system configured as what a real system would be.  That means tons of programs and lot's of tasks running in the background.  If you missed Part I, here's a quick recap of what our system configuration is like for our multitasking tests; the following applications were installed:

Daemon Tools
Norton AntiVirus 2004 (with latest updates)
Firefox 1.02
DVD Shrink 3.2
Microsoft AntiSpyware Beta 1.0
Newsleecher 2.0
Visual Studio .NET 2003
Macromedia Flash Player 7
Adobe Photoshop CS
Microsoft Office 2003
3ds max 7
iTunes 4.7.1
Trillian 3.1
DivX 5.2.1
AutoGK 1.60
Norton Ghost 2003
Adobe Reader 7

What's important about that list is that a handful of those programs were running in the background at all times, primarily Microsoft's AntiSpyware Beta and Norton AntiVirus 2004.  Both the AntiSpyware Beta and NAV 2004 were running with their real-time protection modes enabled, to make things even more real world.


Multitasking Scenario 1: DVD Shrink

For this test, we used DVD Shrink, one of the simplest applications available to compress and re-encode a DVD to fit on a single 4.5GB disc.  We ran DVD Decrypt on the Star Wars Episode VI DVD so that we had a local copy of the DVD on our test bed hard drive (in a future version of the test, we may try to include DVD Decrypt performance in our benchmark as well).  All of the DVD Shrink settings were left at default, including telling the program to assume a low priority, a setting that many users check in order to be able to do other things while DVD Shrink is working. 

Next, we did the following:

1) Open Firefox and load the following web pages in tabs (we used local copies of all of the web pages):

We kept the browser on the AT front page.

2) Open iTunes and start playing the latest album of avid AnandTech reader 50 Cent on repeat all.
3) Open Newsleecher.
4) Open DVD Shrink.
5) Login to our news server and start downloading headers for our subscribed news groups.
6) Start backup of Star Wars Episode VI - Return of the Jedi.  All default settings, including low priority.

DVD Shrink was the application in focus. This matters because by default, Windows gives special scheduling priority to the application currently in the foreground (we will test what happens when it's not in the foreground later in this article).  We waited until the DVD Shrink operation was complete and recorded its completion time. Below are the results:

Multitasking Performance - Scenario 1

The results here aren't too surprising. With dual core, you can get a lot more done at once, so the Pentium D 2.8 cuts the DVD Shrink encode time by about half when compared to the Athlon 64 3500+. 

There is one element that caught us off guard, however. When looking at these numbers, we noticed that they were unusually high compared to the numbers from our first article.  Yet, we ran and re-ran the numbers and had fairly consistent results.  Even running the CPUs at the same speeds as in our first article yielded lower performance than what we saw in that piece.  Comparatively, the processors all performed the same with reference to each other, but the DVD Shrink times were all noticeably higher.  So, we started digging, and what we uncovered was truly interesting.

Gaming Performance The Impact of NCQ on Multitasking Performance
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  • segagenesis - Wednesday, April 6, 2005 - link

    Since I mostly play games ill stick to buying the AMD64 3500+. Thanks. My definition of multi-tasking is using a whole other computer ;)

    The Pentium D seems pretty decent at multitasking as you would define running two things at once but I rarely do that sort of thing since its kind of dumb to encode a DVD in the background while playing a game. Or does encoding a DVD really interfere with browsing the web? I dont know... that and the heat factory output as if it was bad enough is now worse.
  • Woodchuck2000 - Wednesday, April 6, 2005 - link

    #23 - I'm assuming that a dual core A64 at 2.2GHz will blow a Pentium D out of the water at any of the launch frequencies! The Prescott core isn't really designed for multi-core operation, and needs some kind of arbitration logic and some funky-memory-controlling-thingy to work. As a result, the performance improvements in multi-threaded applications aren't anything like the theoretical extra 100% another core could bring. With A64 being designed for multi-core operation I'd expect the increase in performance to be nearer 85%.

    As regards the performance gap between the P4 630 and A64 3500+, the majority of the benchmarks shown here are designed specifically to show performance improvements in multi-core processors. The 630 is hyper-threaded and therefore logically multi-cored, if not physically so. As such the 630 will have artificially high performance compared with the 3500+ - in most single-application benchmarks, the AMD chip would thrash both Intel chips.

    Is there any chance of adding benches for the 630 with HT disabled (or at least giving us an idea of performance.)? We've got a vanilla A64 versus a HT 630 and Dual-core system. It'd be good to see how a single core performs for reference.
  • Anand Lal Shimpi - Wednesday, April 6, 2005 - link

    Jeff7181

    I really can't say more, but you are barking up the wrong tree with those assumptions :)

    AMD's dual core will be quite impressive, even more so than Intel's. Don't look at performance as the only vector to measure though...

    marcusgarcia

    We did look at HT performance when it came out, but the problem is that HT doesn't improve performance in all cases. Look at the Gaming Multitasking Scenario 2 tests, HT reduced performance significantly - most likely because DVD Shrink and Doom 3/Splinter Cell were both contending for floating point resources that were in use. Dual core solves this problem by having two complete sets of execution units, so there's no worry about contention between threads for shared resources.

    As far as Half Life 2 goes, it is still single threaded so its performance characteristics would be no different than what you see here.

    mlittl3

    I've been looking into running VoIP or some sort of voice chat program in the background, the problem surfaces in trying to put together a reliable, repeatable workload. Dual core will most definitely help there, but how much - I do not know.

    I haven't given up yet :)

    BruceDickenson

    Glad to have you on-board and thanks for the kind words :)

    Woodchuck2000

    The new dual core chips are still LGA-775, but they do require a new motherboard (unlike AMD's solution which just requires a new BIOS). Currently Intel's 945 and 955 chipsets will support dual core, and tomorrow I should have a nForce4 SLI Intel Edition board that will support dual core as well. The new NVIDIA chipset does support dual core, but it's up to motherboard makers to implement support for it in their designs.

    Check with the motherboard maker to make sure that dual core is explicitly supported by the board, it should say so somewhere in the manual or on the box.

    Take care,
    Anand
  • Jeff7181 - Wednesday, April 6, 2005 - link

    #22... Anand said a 2.2 GHz Athlon 64 won't compete with the 2.8 GHz Pentium D. That either means a 2.2 GHz dual core Athlon 64 will have lackluster performance, or it will be AMD's new enthusiast line like the FX is right now, which means it would be competing with the Extreme Edition chips, not the regular line.

    I guess there's a 3rd possibility. He was referring to dual core Opterons which obviously won't compete with the Pentium D any more than the Opteron competes with the Pentium 4 right now.
  • Woodchuck2000 - Wednesday, April 6, 2005 - link

    Just out of interest, does anyone know what socket do the new cores use? Will the new nVidia chipset support the new cores (it was hinted at briefly, but not stated explicitly...)?

    #19 - What's your source for those assertions? I've heard reports that AMD have got samples running at well over 2GHz and since the K8 architecture is natrually better suited to multiple cores I'd have expected blistering performance. BTW, does anyone know if the AMD cores will be based on the new Venice rev? Is SSE3 a given?
  • BruceDickenson - Wednesday, April 6, 2005 - link

    Hey all, long time reader, this is my first "post"/comment...

    Just had to say this is one of the most interesting articles I've read in a long time. I loved the NCQ tangent, it almost felt like you were part of a conversation when you read how Lal Shimpi analyzed the anomaly in his testing.

    Loved it! Thanks AT!
  • marcusgarcia - Wednesday, April 6, 2005 - link

    14# again.

    Forgot to say in the last post, my rant is about HT, not dual cores.

    I know 2-cores won't make THAT difference on these trivial things (who needs another 2.8ghz for simple stuff?)...but..HT is benefiting GREATLY from it, yet noone mentioned it and didn't even try this sort of test when HT was launched.

    When you see the 3.0 HT doing better than a AMD 3500+ (supposedly 500 points faster), you gotta ask how badly would it beat the AMD 64 3000+, which happens to cost almost the same than the P4 3.0 ghz...which happened to destroy the much faster AMD on the test.

    That pretty much sucks and leave us with the impression that people either:

    a - wanted to benefit AMD
    or
    b - were too ingenuous to think on these tests when doing HT tests (which can't be true because i always wanted them)
  • Jeff7181 - Wednesday, April 6, 2005 - link

    Errr... correction...

    1.) The dual core 2.2 GHz Athlon-64's will be less than impressive and won't even perform in the same class as a Pentium D @ 2.8 GHz.

    2.) The mainstream Athlon-64 dual core chips will be running at much less than 2.2 GHz, and the 2.2 GHz dual cores will be the FX line, which compete with the Extreme Edition Pentiums.
  • marcusgarcia - Wednesday, April 6, 2005 - link

    14#

    Completely wrong.

    1º: Outlook checks 8 pop accounts for mail and apply it's rules to it every minute or so.
    2º: MSN with webcam can eat quite some CPU, specially because i play on the dark with the "low light filter" turned on, which happens to eat quite some CPU.
    3º: For every file opened/closed both the AVG and the MS anti-spyware are going to have a check if that's malicious and if the action is allowed.

    When i close everything and run 3dmark01 i get around 300 - 600 more points out of it from my 12200 points score.

    PS: don't forget IE, which is usually opened here or on tom's hardware (or both and some more), which happen to have a lot of those huge flash banners.

    I think that DOES make *a lot* of difference.

    Add to that the fact of many people using skype while gaming, mainly on FPS and RTS, which can make all the difference.
  • Jeff7181 - Wednesday, April 6, 2005 - link

    "Let's just say that the dual core Athlon 64 running at 2.2GHz won't be compared to a dual core Pentium D running at 2.8GHz."

    So you leave two possibilities.

    1.) The dual core 2.2 GHz Athlon-64's will be less than impressive and won't even perform in the same class as a Pentium D @ 2.8 GHz, but rather dual core Extreme Edition chips.

    2.) The desktop dual core Athlon-64's will be running at much less than 2.2 GHz.

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