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  1. Member wulf109's Avatar
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    There seems to be one task were AMD cpu's excel. Using BDrebuilder in High Speed BD25 mode which only performs the second x264 pass. I recently assembled a 1090T 6-core computer and it seems to be about 20% faster than my i7 system. I did a 4 hour episode disk using the AMD and it took 107 minutes,which seemed fast. I did the same disk on my i7 and it took 144 minutes. The AMD was much faster. i7 running at 3.6GHZ and the AMD 1090T running at 3.8GHHZ.
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  2. Yes, that would jive with what all the benchmarks have shown.

    Of course, the i7 920 isn't the current competitor for the 1090T. The i5 2500K is. It's in the same price range and runs the x264 second pass only a little slower than the 1090T (at stock clock speeds). The i7 2600K handily beats the 1080T but costs $100 more.

    You might find this interesting (though not applicable to the 1090T): Microsoft released a new task scheduler for Win7 that improves Bulldozer performance by 2 to 7 percent. There was some problem so they withdrew it but I suspect it will be back soon.

    http://www.anandtech.com/show/5251/microsoft-releases-hotfix-to-improve-bulldozer-performance
    Last edited by jagabo; 17th Dec 2011 at 21:52.
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  3. You must be running an aftermarket cooler to get it up to 3.8 GHz.

    Anyway yeah, that CPU really goes when running x264 encoder. And it's no slouch on other tasks either, even if roughly comparable Intel CPUs beat it in most benchmarks.

    I went with the 1090 Thuban because Newegg offered me a promo on it for 160 bucks. What sealed the deal was the fact that AM3 mobos were considerably cheaper. But I guess what it really comes down to is I just wanted to bypass Intel this time. I don't regret it one bit.
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  4. Member wulf109's Avatar
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    I'm using a cooler-master push-pull HSF. I was running at 4.0GHz but I would sometimes get 264 errors or reboots. I dropped it to 3.8 and set the vcore back to default,was running with .1 bump on the vcore. 3.8 at default vcore has been rock solid. We must have bought the 1090T at the same time because I paid $160.
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    I have an AMD Thuban 1055 overclocked to 1090 speeds and have been pleased with the results I get in BD Rebuilder, but there was an interesting development with Intel Quick Sync and ffdshow. One of our mods over at MyCE uses an Intel i7 and was getting some incredible times from her machine and BD Rebuilder: http://club.myce.com/f142/bd-rebuilder-intel-quick-sync-324433/
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  6. Originally Posted by wulf109 View Post
    I'm using a cooler-master push-pull HSF. I was running at 4.0GHz but I would sometimes get 264 errors or reboots. I dropped it to 3.8 and set the vcore back to default,was running with .1 bump on the vcore. 3.8 at default vcore has been rock solid. We must have bought the 1090T at the same time because I paid $160.
    There's the luck of the draw for you. Mine requires a v-core bump to go from 3.4 GHz to 3.5. Otherwise, x264 bombs. BTW, it's been my experience that Prime95 is a darn good test of OC stability. If it runs 15 minutes without crashing, you're good.

    I had mine up to 3.6 Ghz on the stock cooler, but backed away. Not because of fan noise (it *IS* rather loud under load) or temperatures (still under 50 C), but because...oh I dunno, it's plenty fast enough at 3.5 Ghz. Each step up in clock speed while overclocking was a matter of diminishing returns. Pretty big difference between, say, 3.2 and 3.3 GHz; not so much between , say, 3.5 and 3.6 GHz.

    The stock cooler isn't bad at all. The noise I can stand, because an encode only takes about an hour, and I'm not doing anything with the computer anyway when the processor is pegged at 99-100%. When not encoding, I don't recall ever getting above 10% CPU usage, and the fan is reasonably quiet.

    The anandtech article is interesting. If I'm understanding it correctly, the improvement comes from more efficient scheduling, which allows cores to be idled and turbo core to kick in. The bump is all about turbo core.
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  7. Member wulf109's Avatar
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    I've always believed CPU's have a "sweet spot" beyond which increasing BUSS speed doesn't increase performance. My 1090T seems faster ay 3.8 than at 4.0. My test disk dropped to 101 minutes instead of 107 at 4.0
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  8. Mod Neophyte Super Moderator redwudz's Avatar
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    I've found a lot of AMD CPUs can benefit greatly from just a small OC, maybe 10%, and that seems to be a visible improvement in performance without overheat or stability problems.

    But higher OCs can be workable if you have sufficient cooling. I used a Corsair H-50 water cooler on my AMD X6 1100T black edition and OC it to 3.7Ghz from the stock 3.3Ghz. With the water cooling, it runs about 40C under full load and it's very quiet. I tried higher OCs, but then I had to adjust voltages, etc., to get stability, and I didn't see that much additional gain in performance.

    I decided to pass on the 8 core AMDs for the present. I didn't want to get a new MB and RAM. Maybe later.

    I don't use Rebuilder, but I do use RipBot and Handbrake a lot, both using MKV for output. The six core has cut close to an hour off my BD>MKV (Two pass) encodes compared to the four core AMD I was using at a similar speed. Good enough for me.
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