[G4] New G4 1.73s! Questions!

[Mel Krewall]

This is copied from today's xlr8yourmac.com news:

> "GigaDesign comments on 1.7GHz 7447A Upgrade performance (vs 7455 
> upgrades w/L3 cache) - (from a reader mail last night)
>
>     "On a discreet page, Giga designs admits that the 1.73GHz 7447 
> upgrades are no faster than a 1.467GHz 7455. It seems that the lack of 
> level 3 cache offsets the 18% clock increase.
>     The new chips, however, do draw less power. (much less)
>     http://www.gigadesigns.com/newsMDD7447.html
>     -Tyler W. "
>
> Past tests with 745x CPUs/upgrades with no L3 cache (compared to the 
> same speed upgrade w/L3) showed a big hit in performance in some tests 
> - especially 3D gaming. Those were 256KB L2 CPUs, not 512KB like the 
> 7447A, but I'd still prefer an upgrade with an L3 cache for older 
> Macs. GigaDesign mentions the much lower power use (40% they say) of 
> the 7447 as a plus for Cube owners and earlier model AGP Tower owners 
> that didn't have very high wattage Power Supplies. (The Cube's power 
> brick for instance is rated for 208W (28VDC), and as mentioned in past 
> full reviews here of Cube upgrades - if you're running an ADC display 
> that also consumes a portion of that power budget and in some cases 
> has caused failures/damage when upgrades were used w/ADC monitors - in 
> particular the 17in CRT ADC display, which uses about half of the 
> total power budget. I've seen some failed VRM boards reported also 
> with heavily upgraded Cubes and they're expensive to replace typically 
> - over $200 apple parts list price last i checked a couple of years 
> ago. Although more robust VRM boards were originally promised by two 
> companies, to date they were never sold. I remember someone using a 
> 2nd Cube Power brick for ADC power IIRC, but most owners are not going 
> to do those sorts of mods.)
>
> As mentioned in Tuesday's news (when Sonnet's and GigaDesign's 7447 
> upgrades were announced), Sonnet's ST G4 product page has a link to a 
> benchmarks page but it has no comparison results (to date) with the 
> 1.7GHz upgrade. (If any readers buy one of these please post a report 
> in the database here. Running some before/after apps tests would also 
> be nice to include - see examples in reviews on the CPU upgrade 
> reviews page here. Thanks.)"

I went to the page linked above and it seems that you do not get a 
great deal of extra speed because it has no Level 3 cache. This is 
pretty consistent with my experience, as my G4 eMac 1 GHz which has no 
Level 3 cash is not as fast as my 933 MHz Quicksilver 2002, which does 
have L3 Cache.

Mel

"They say golf is like life, but don't believe them. Golf is more 
complicated than that."
  ~Gardner Dickinson

On Dec 8, 2004, at 11:46 PM, Nicolas Kinnan wrote:

> Howdy,
>
> Anybody here know if the new GigaDesigns Dual 1.73GHz G4 upgrade 
> boards, which don't have any L3 cache, would be significantly faster 
> for DV and 3-D shooters, than the older dual 1.33GHz units that have 
> 2MB of L3 cache per chip?
>
> I can't seem to find any tests that show, clearly and simply, what 
> kinds of advantages big L3 cache provides and doesn't provide.
>
> Also, one of these 1.73 upgrades is a pair of over-clocked 1.43GHz 
> chips, while its much more expensive stable-mate is made up of two 
> OC'd 1.6GHz units.  Is there any scientifically sound reason to 
> suspect that the 1.6-based units my be more durable due to lower 
> stress?
>
> I figure this is all a shot in the dark as these are so new, but I am 
> hoping someone here knows what there is to know about it all.
>
> Thanks in advance,
>
> Alex