Sorry - a few more details that I should have included...
Image Squeak3.7 latest update: #5989
Desktop size 1268@927 (just what it happened to be)
OS Windows XP Pro SP2, fully updated, in all cases
Some VM settings DeferUpdate=1 ReduceCPUUsage=1 ReduceCPUInBackground=0 PriorityBoost=1
I *guess* that the display chip is the largest variable here, after all it needs to do all the actual copying of data.
Yup, presumably. But I was surprised at the broad disparity. Another candidate that I tried (a new Panasonic laptop, that I don't have access to at the moment) seemed to be taking nearly ten times as long as the Toshiba!
Maybe the answer is something like "Oh, nobody runs the Panasonic with the default device driver; you need to download the latest from ...". But I wanted to check with the list in case this was a known phenomenon in porting Squeak.
All the best
Aran
Am 21.06.2005 um 16:46 schrieb Aran Lunzer:
1268@927 (just what it happened to be)
Display depth? Host display depth?
Make sure both match. Setting both to 16 might help, it's half the data. Both at 32 might or might not be faster. On Intel, using an LSB display might help (see appearance - display depth).
At 1280x1024x32 you are pushing 5 MB each frame down the graphics bus. PCI bus is 33 MHz and 32 bits wide, giving you 165 MB/s bandwidth max, which means 33 ms per frame. AGPx4 is only 4 times faster, giving you 8ms/frame, AGPx8 then 4ms. As simple as that.
- Bert -
Am 21.06.2005 um 19:10 schrieb Bert Freudenberg:
Am 21.06.2005 um 16:46 schrieb Aran Lunzer:
1268@927 (just what it happened to be)
Display depth? Host display depth?
Make sure both match. Setting both to 16 might help, it's half the data. Both at 32 might or might not be faster. On Intel, using an LSB display might help (see appearance - display depth).
At 1280x1024x32 you are pushing 5 MB each frame down the graphics bus. PCI bus is 33 MHz and 32 bits wide, giving you 165 MB/s bandwidth max, which means 33 ms per frame. AGPx4 is only 4 times faster, giving you 8ms/frame, AGPx8 then 4ms. As simple as that.
Err, AGP is clocked at 66 MHz, so double those numbers ... AGP is fast. But of course, the driver has to make the CPU and chipset deliver your data to the graphics board efficiently. Which not all combinations of hardware and software do equally well.
- Bert -
1268@927 (just what it happened to be)
Display depth? Host display depth?
Make sure both match. Setting both to 16 might help, it's half the data. Both at 32 might or might not be faster. On Intel, using an LSB display might help (see appearance - display depth).
Thank you, Bert - that was the problem.
I run Squeak with 32-bit colour, but on the suspiciously slow Toshiba the Windows setting was 16 bits. Changing Windows to 32-bit colour won a factor of five speed-up (I wonder why five?).
Very happy. I had wanted to buy that model of laptop anyway, but couldn't do so while Squeak performance seemed so poor...
Best wishes -
Aran
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