Drobe :: The archives
About Drobe | Contact | RSS | Twitter | Tech docs | Downloads | BBC Micro

Reply to thread

Think I've realised why you might see this differently.

On OS 4 you cannot easily queue the commands. On OS 6, command queueing is used on both R128 and VPod (because of the use of data aborts to stall and unstall the pipeline when direct memory access occurs), which is why the OS 6 performance is faster for all cards.

In isolation, I agree you'd see little difference. But when you queue them together, polyhline operations are significantly faster than their direct memory access fill equivalents, and yet the podule bus is still the bottleneck here.

As Rob's pointed out, podule bus logic may also come into play.

In either case, the numbers will speak for themselves - would anyone care to write a quick BASIC app or two to test graphics drawing ops on the different drivers?

 is a RISC OS Usermd0u80c9 on 20/8/09 9:51AM
[ Reply | Permalink | Report ]

Please login before posting a comment. Use the form on the right to do so or create a free account.

Search the archives

Today's featured article

  • A9home DIY laptop: first pictures
    And other odds and sods from the Christmas 2007 show
     22 comments, latest by sa110 on 1/6/08 4:47PM. Published: 1 Dec 2007

  • Random article

  • Charity stall confirmed for Wakefield
    Can you smell what Wakefield is cooking?
     Discuss this. Published: 28 Mar 2006

  • Useful links

    News and media:

    Top developers:
    RISCOS LtdRISC OS OpenMW SoftwareR-CompAdvantage SixVirtualAcorn

    CJE MicrosAPDLCastlea4X-AmpleLiquid SiliconWebmonster


    RISCOS.org.ukRISCOS.orgRISCOS.infoFilebaseChris Why's Acorn/RISC OS collectionNetSurf

    Non-RISC OS:
    The RegisterThe InquirerApple InsiderBBC NewsSky NewsGoogle Newsxkcddiodesign

    © 1999-2009 The Drobe Team. Some rights reserved, click here for more information
    Powered by MiniDrobeCMS, based on J4U | Statistics
    "'Only the truly memorable stunts are worth a write up'. So, what sort of memorable 'stunt' might be worth a write up?"
    Page generated in 0.0325 seconds.