Date:	Fri, 28 Nov 1997 22:07:47 +0800 (GMT)
From:	Orlando Andico <orly AT dilnet DOT upd DOT edu DOT ph>
To:	rkramer AT xs4all DOT nl
cc:	djgpp AT delorie DOT com
Subject:	Re: Blit timing - complicated?
In-Reply-To:	<65m5fp$k73$1@news2.xs4all.nl>
Message-ID:	<Pine.SGI.3.96.971128220517.5365A-100000@gibson.eee.upd.edu.ph>
MIME-Version:	1.0

On 28 Nov 1997 rkramer AT xs4all DOT nl wrote:

> Hi All,
> 
> In a discussion with a friend of mine, he was trying to convince me that it's
> possible to blit a full 800x600 screen in less than a millisecond. I tried to
> tell him otherwise, but couldn't quite get my point through :)

800x600 = 480000 bytes = 0.5MB

to blit it in less than 1ms, you need (1000)(0.5MB) = 500 MB/sec bandwidth
to your video bus. PCI bus maximum speed is 200.. MB/sec. this never
happens. the only buses which might be able to sustain 500 MB/sec are the
Unified Memory Architecture on new-model SGI boxes, and the UPA/Firetruck
Bus on the Sun Ultra.

regardless of MOV.. speed, you're limited by how fast the CPU can transfer
the bytes to the video card.


-------------------------------------------------------------------
Orlando Alcantara Andico              Email: orly AT dilnet DOT upd DOT edu DOT ph
ICBM:  14 30 00 N  120 59 00 E               POTS:  (+632) 932-2385
"If I shed a tear I won't cage it, I won't fear love, and if I feel
 a rage I won't deny it, I won't fear love."      - Sarah Mclachlan

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