GPU choice - handbrake encoding using hardware GPU 775M vs GTX 780M

Discussion in 'iMac' started by TwoBytes, Oct 4, 2013.

  1. TwoBytes macrumors 68020

    TwoBytes

    Joined:
    Jun 2, 2008
    #1
    When planning my new 2013 iMac the only thing i'm debating is the GPU.
    I don't play games but do a lot of encoding.

    I read that handbreak uses Hardware Acceleration to speed up encoding which wasn't the case in older versions. Does anyone know what kind of percentage of speed this adds? I may just opt for the 780 just for resale value in the next couple of years..


    Mods, hope this is the right forum opposed to ATV or Video? Couldn't decide. Thanks :)
     
  2. Nightarchaon macrumors 65816

    Nightarchaon

    Joined:
    Sep 1, 2010
    #2
    I was looking into this, in the end i built a PC for about 50% the cost of the top end iMac with more ram, more HDD Space, a faster CPU, expansion space and SLI 670s that given CUDA aware conversion software chew through my video conversion needs in a way nothing but an old school mac pro would.

    Kept my 2011 iMac for pretty much everything else, except gaming, watching blu-rays, and 3D gaming and movie watching (Passive AOC 27" 3D screen FTW)

    In fact my iMac has become an iTunes server for the house, a place where i do my "productive" tasks with word and excel, and deal with my emails and browse the web, little else as everything else i do on the better equipped PC

    ill always advise people who are looking for a 1st home computer to get an iMac, if they want to word process, browse the net, and maybe even watch netflix.

    The iMac also has the benefit of keeping my electricity bills low, as its not chewing through 800w all the time.

    For gaming, heavy/quick video conversion (not editing) and pretty much anything else, i advise a PC.
     
  3. chevalier433 macrumors 6502a

    chevalier433

    Joined:
    Mar 30, 2011
    #3
    handbrake depends on cpu cores.780m is mainly for gaming.
     
  4. Nirurin macrumors member

    Joined:
    Oct 3, 2013
    #4
    How?

    I recently have been looking at (and trying to decide between) making a hackintosh vs buying a 27" imac. Price being the deciding factor.

    But half price? The build I had was £1150, and that was only a single 670. another 670 would add another £200+. And a 1440p monitor is another £450. So thats £1600 total. (£1800 with the second 670.)

    Yes, its a lot more powerful graphically, and has more storage on board, but its not half the price... its only about £300 different. Unless you already had a monitor of course (I dont).

    Was just curious.
     
  5. TwoBytes thread starter macrumors 68020

    TwoBytes

    Joined:
    Jun 2, 2008
    #5
    Back on topic, does any tech head know if the graphics card impacts handbreak as well as CPU?
     
  6. martinm0, Oct 4, 2013
    Last edited: Oct 4, 2013

    martinm0 macrumors 6502a

    Joined:
    Feb 27, 2010
    #6
    My experience with a variety of machines tells me no. Sure, it helps maybe a little, but not enough to be the only reason to get the updated card.

    Take a look at some of the Sandy Bridge Big Buck Bunny Handbrake benchmark threads here on MR and you'll see a number of posts I did comparing a variety of machines (rMPB, Mac Mini, Hackintosh, etc). If I recall correctly, I pitted the first gen Mac Mini with i7 and i7 MBP and found that the MBP beat it out slightly. Then when I tested a new 2.6 i7 Mac Mini to my current gen i7 2.7 rMBP, the Mini was a little faster. Odd.

    http://forums.macrumors.com/showthread.php?t=1111126 (see the last few pages for more current benchmarks)
     
  7. Nirurin macrumors member

    Joined:
    Oct 3, 2013
    #7
    Ahh yes sorry, went off topic a tad there..

    I have tried researching into handbrake myself on this issue, and it seems that the GPU can/does effect handbrake times, as it now uses OpenCL.

    But, whether theres a big difference between the 775 and the 780, I dont think theres an easy way to calculate it.

    Will have to find a couple nice people who have these two GPUs, and ask them both to handbrake the same file, at the same settings, and see what the results are, I expect?

    If/When I get my machine, I'll be happy to be a guinea pig, but I expect people will come up with the answers by then :)
     
  8. FredT2 macrumors 6502

    Joined:
    Mar 18, 2009
    #8
    It's long been known that Handbrake does not use GPUs at all. It's all in the processors, and it will push those to the max. So if Handbrake is the app that needs to be fast, get the fastest CPU and don't worry about the GPU
     
  9. Nirurin macrumors member

    Joined:
    Oct 3, 2013
    #9
    Really? I've found a fair few references to handbrake using gpu, including on the handbrake site itself. Though I'll admit I dont necessary understand *how* its using the GPU, but still.
     
  10. Nightarchaon macrumors 65816

    Nightarchaon

    Joined:
    Sep 1, 2010
    #10
    670s cost me £180 each with some careful shopping, the entire rig was new, and i settled on two 1080p AOC Passive 3d monitors, costing £380 the pair, i have no need for higher than 1080p as main screen displays the video im working on natively at 1080p and 2nd screen has the applications open

    the choice of monitor was the "cut price" shot to drive down the price, the iMac i was looking at topped out at in excess of £3000 when apple care and cabling + Thunderbolt chassis was added to drive the raid that the PC has now got internally . My boot is off a 128GB SSD that i picked up for £54 on a special at scan, im using intel RST with a sperate 60gb SSD i got for a ridiculous £40 in a bargain bin in PCworld, and the 4TB raid array cost me £180.

    Keyboard + Mouse price i wasn't including in that (my mouse cost £109, keyboard , £200) Total PC build came in around £1500-£1600 without them all new parts (and i wasn't including OS in that pricing)

    If you take out the Raid, then the prices do come a lot nearer, but the iMac is such a pain to upgrade and use in a professional environment, and god forbid anything on it broke, it would grind my work to a halt for days (One of the reasons i built this PC and ignored the new Mac Pro, cant afford the apple level of downtime a fault would cause)
     
  11. Bear macrumors G3

    Joined:
    Jul 23, 2002
    Location:
    Sol III - Terra
    #11
    The link that the OP provided talkes about handbrake and GPU usage.

    Again, look at the link the OP provided.
     
  12. Nirurin macrumors member

    Joined:
    Oct 3, 2013
    #12

    Ahh yeah, thats the same wiki page i was looking at.
     
  13. mcnallym macrumors 6502a

    Joined:
    Oct 28, 2008
    #13
    http://handbrake.fr/news.php

    The use of OpenCL or Intel QuickSync are beta versions only, and Windows

    OpenCL only accelerates at the moment if downscaling your Video.
    QuickSync is Windows only and uses the iGPU in the CPU.

    The regular release still uses CPU for the Encoding.

    It won't make any difference to the user which of those GPU's buys in relation to his Handbrake Encode time.

    The hardware acceleration talked about in the linked info is for hardware DECODING. My 2008 MBPro 9600GT or 9400m can keep up fast enough for that
     
  14. TwoBytes thread starter macrumors 68020

    TwoBytes

    Joined:
    Jun 2, 2008
    #14
    Thanks for these replies, it looks like CPU still dominates with encoding jobs. i7 is on my shopping list :)
     

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