The Low End Mac Mailbag

More G4 Upgrade Advice, Secure Disk Wipes, 500 MHz iMacs with Tiger in Action, and More

Dan Knight - 2008.05.09 - Tip Jar

More G4 Upgrade Advice

From Felix Lizarraga:

Hi Dan,

I would like to comment on Paul Lewis' question. IMHO, for the kind of money one has to shell out for a CPU upgrade, it's possible, and more cost effective, to get a nice MDD that can run Leopard natively, or even a gently used Intel mini that will chew up H.264 codecs like Wrigley's. Just my two cents.

Anyway, congratulations on the site. I have been addicted for years, and it just keeps getting better. Kudos to you and the rest of the bunch.

Felix Lizarraga


Thanks for the kind words.

You make a good point. Paul could buy a nice used MDD Power Mac G4/1.25 GHz dual for about $600, max out RAM to 2.0 GB for about $80, then transplant the video card and other goodies, put the Radeon 9000 from the MDD into his Digital Audio, and probably sell it for $300 or so with 1.5 GB of RAM and a better-than-stock video card. Net cost could be under $400 vs. spending $400-500 for a CPU upgrade.

Of course, he would have quite a bit more processing power with that dual 1.8 GHz upgrade....


Hi Dan,

Wow, quick response! You seem to have it all figured out. :-)

I personally had a bad experience with a CPU upgrade, although I know plenty of people who use them with no issues. It was a (now rare) dual 1.2 GHz that gave me nothing but kernel panics and freezes. OWC eventually replaced it, but I sold the replacement on the LEM swap list - the new owner is a happy camper to this day, so your mileage will vary.

After another horror story with a hard drive-serial-killer Quicksilver (has it happened to anybody else?), I ended up getting a dual 1 GHz MDD like yours. These things are rock-solid, and, boy, are they fast. Mine has 1.75 GB of RAM, but I haven't really felt the need to bring it up to 2 gigs.

Now, for dealing with video, no G4 CPU will give Paul the processing power of Intel. Like you said a few days back, even the lowest of the lowest, the Intel Solo mini, will run circles around any G4 in that particular terrain.

Best regards,


I've had great luck with upgrades over the years: Sonnet 68040 upgrades for the Mac IIci, several different G3 upgrades for PCI Power Macs and Umax SuperMac clones, and the NewerTech 1.8 GHz G4 upgrade I reviewed earlier this year.

As for my MDD Power Mac, it's rock solid - and the only reason it has 2 GB instead of 1.75 GB is that it uses the same RAM as my 1.25 GHz eMacs, so when one of them died, I replaced a 256 MB module with 512 MB.


7447 vs. 7448 G4 Upgrades

From John Black:

Hi, Dan,

I was just reading your 5/7/08 "Low End Mac Mailbag" entry from yesterday. Regarding the question about dual Sonnet 7447 processors vs. single 7448, I think both and OWC have tests and comparisons on some systems, though I don't remember if there's a dual 7447 comparison.

I also have a DA 533. A year ago I put a Sonnet 1 GHz 7445 (I believe) single processor in our DA, which noticeably sped things up. However, back in November I read about the new 7448 processors that OWC was marketing. After some investigation, I concluded that the 1.7 GHz 7448 offered the best combination of price and speed. It has not disappointed. Talk about a powerful processor, the 7448 is awesome. I've grown so used to the power that I think I'd have a hard time doing without it. It puts the Sonnet 1 GHz card in the shade.

I think the only real bottlenecks in the DA now are 1) bus speed, at 133 MHz, and 2) video card. Can't do anything about bus speed, but I have replaced the stock Rage 128/16 MB video card with a Radeon 9000 Pro/128 MB card. This card makes redraws, video clips, and graphics handling much better. Still, however, the slow bus and limited Radeon are put to the test with my son's upload of digital picture files from a Canon 30D. The Macs at school are Intel iMacs, which have a lot more power for that type of task, so his patience is challenged with the DA.

Anyone using a G4 tower ought to consider the OWC 7448 processors. For ordinary usage, I can't recommend them strongly enough.

John Black


It's hard to find head-to-head comparisons of the 7447 and 7448, but I've found a good one on Bare Feats. It compares a single 2.0 GHz 7447a, a single 2.0 GHz 7448, and a dual 1.8 GHz 7448 with the dual 1.42 GHz Power Mac G4 and a dual 2.0 GHz Power Mac G5 (even throwing in the 2.0 GHz iMac Core Duo to show how far behind PowerPC power is nowadays).

Overall, the 7448 beat the 7447A by 3-10% on most tests, and the 1.8 GHz dual 7448 outperformed the 2.0 GHz single 7448 except in the Doom 3 benchmark. Two processors at 1.8 GHz was 33% faster on the Cinebench test than one 2.0 GHz. If we normalize for CPU speed, two processors provides 37% more power than one for Cinebench at the same clock speed.

The single 2.0 GHz 7447A matched performance of the dual 1.42 GHz Power Mac G4 on two of four tests - dual CPUs helped the dual 1.42 smoke the single 2.0 under Cinebench and iMovie. As I've often said, a dual G4 will generally match the performance of a single G4 that's 50% faster (ignoring differences between the 7455, 7447, 7448, etc.).

With its much faster memory bus (1 GHz vs. 133 GHz for G4 Power Macs), the 2.0 GHz dual Power Mac G5 matches or beats the 2.0 GHz dual G4 upgrade on all benchmarks, and the consumer 2.0 GHz Core Duo iMac beats any of the G4 upgrades, showing how far we've come with the Intel transition.

For me, it's all a question of how much the additional horsepower will improve your productivity. If you're taxing one or two 533 MHz or 1 GHz CPUs, it may be sensible to invest $400-600 in a high-end G4 upgrade - or it may make more sense to pick up a used or refurbished Mac mini in the same price range, gaining Intel power you can use alongside you G4 Power Mac.

As for uploading digital pictures, have you looked into a USB 2.0 card for the Power Mac? They're cheap and a lot faster than the USB 1.1 built into G4 Power Macs.


Secure File Erase for Old Macs

From Steve Lubliner in response to Deleting Files from a Performa 6300:


Putting a file in the Trash and emptying the Trash does not delete the file from the hard drive. The file can be recovered using "Unerase" functions in programs like Norton Utilities (note that OS X 10.3 and later have "Empty Trash" and "Secure Empty Trash" options). The best way to destroy secure information on a hard drive is to destroy the hard drive, e.g. with a sledge hammer. If the computer is to be recycled (as opposed to reused), then this is the easiest approach. If the desire is to keep the computer functional, then the best approach is to reinitialize the hard drive including writing "0"s" and "1"s" to the drive to overwrite any drive data. Once that is complete, then the drive can have a new operating system installed.

Steve Lubliner


You make a good point. When a file is deleted, only the pointers to it are removed. The actual data remains on the hard drive unless you use some sort of secure delete program - and the Mac didn't have that in the Performa era. The closest you can come without third-party software is reformatting the hard drive and zeroing all data - and then writing a fresh copy of the operating system to it. Because IDE drives aren't completely cleared during formatting, this will have the effect of overwriting much of what was on the hard drive, making it difficult (but not completely impossible) to recover.

There are two shareware programs for the paranoid (and we should all be a bit paranoid about personal information these days): ShredIt (available in Mac OS 8/9 and OS X versions - the unregistered version does not shred) and The Eraser Pro, which supports Mac OS 7-9 - and the unregistered version works.


Wipe That Drive before You Give Away Your Mac

From John Carlson:


I just read your response to Charles Jobe, who wants to delete personal files from his computer before giving it away. (A good idea - and one that many people don't think about. I'm surprised at how many used computers have come my way that have personal files of some sort left by the previous owner.) However, it's worth noting that tossing files into the Trash and then selecting "Empty Trash" won't totally remove the file. It can still be recovered by a file recovery utility.

Reformatting and installing the OS from scratch is probably safer - although I imagine that someone with the knowledge and the tools could recover files. For the more paranoid, there are various utility programs that do a more complete erase. Every now and then, I see an old copy of, say, Norton turn up. (The LEM Swap List can probably help here.)

John Carlson


Good point. All that's really required to effectively clear the old data is a program that writes random data to every unused sector. The secure delete option in OS X is more than adequate for deleting files, and both Disk Utility (OS X) and Drive Setup (Classic Mac OS) have a built-in option to zero all data when reformatting a hard drive.



Drive Setup should be adequate for removing data. I didn't remember that Drive Setup had such an option. (I've been using Macs since System 6, and the details of what's available begins to blur after a while!)

Another point worth bringing up for those who donate old computers to thrift stores: thrift stores (at least the ones where I live) don't do anything towards removing old data. Whatever is on the hard drive when donated will still be there when the computer is put up for sale. Thus, a person donating an old computer should take the time clean off the hard drive. I'd do this even if I was donating to someone who promised to clean the drive.

John Carlson


I am also rusty on the Classic Mac OS. I had to boot my iMac into OS 9, launch Drive Setup, and look for the "zero all data" option. I don't know how far that option goes back.

I agree completely on wiping the hard drive before you give away or sell a computer - and you may even want to use it when you move your computer to another family member.


Pismo Should Be Safe with the Lid Closed

From James Haudenshield:


Ken Watanabe wrote:

One additional note: Once it starts or wakes up in this mode, you can (and probably should) open the lid. The Pismo's LCD screen will stay dark and the display mode will not change. I was concerned about operating my Pismo with the screen down, because the CPU heat sink is right under the keyboard and dissipates heat up through the keyboard. Since my Pismo has a G4 in it, the heat somewhat higher. I didn't want to damage the LCD or cause unnecessary use of the fan. A possible warning for your readers....

I've been using my Pismo in the lid-closed mode for quite a while, and there are a number of tech articles at Apple that discuss it (although they've gotten difficult to find recently - I'll forward the article numbers if I can find them tonight). I was delighted to find that modern standard and widescreen 19" flat panel (VGA/EGA/SVGA) monitors were fully supported at max resolution at "millions" of colors, even though this PowerBook model is so old. The additional resolution options don't appear in the display controls until the monitor is attached. A couple of issues that ought to be clarified on this process, for the Pismo, are:

  1. You should should use a keyboard that has a power button on it. Connect the keyboard, monitor, and mouse while the Pismo is off. Then power up the monitor and press the power button on the keyboard to startup the Pismo. (This isn't for safety, it's just so the Pismo shifts to the external monitor correctly.) It will automatically use the attached monitor and does not turn on the built-in display. If your keyboard doesn't have a power button, you can either get everything connected, then hit the Pismo power button and quickly close the lid, or restart the Mac, closing the lid immediately when the screen goes blank during the restart.
  2. It is completely safe to leave the lid closed on the Pismo while using the external monitor, with no worry of overheating. Because the built-in monitor is not even active, it keeps relatively cool. If the motherboard does warm up, the built-in fan may come on periodically, depending upon your room temperature (which might startle you at first if you've never heard it kick-in before). Worry not, the PowerBook is designed to be used with the lid closed.
  3. When shopping for monitors, don't even bother asking any salespeople anywhere about whether a particular monitor will work for you. Even many Mac experts don't know. The salespeople at some places will sometimes even just ignorantly say that it won't because "it's a PC monitor". Just be assured that if it's got the standard VGA (non-digital) connection, you can connect it and it will work (up to at least 19" size, in my experience). If you get a monitor that has speakers, like some HP models or some Westinghouse models, you can connect your speaker-out port to the monitor, and it will work also (you won't hear your built-in speakers very well because the lid is closed and covers them). If you get a monitor that has a USB hub, such as one sold at Staples, it is likely not a powered USB hub, so you will have some limits on what you can plug in (some flash drives will work, others won't).
  4. If you're trying to simply extend your desktop space by using both an external and your built-in monitors, then you need to have the lid open when powering up the Pismo. Because of the extended desktop space, your color depth may be reduced or resolution limited [on the external display].

- Jim

PS: Admittedly, Ken's Pismo has a G4 in it and he might well worry about increased heat - I don't mean to suggest that such modified machines can't benefit from additional cooling. But standard G3 Pismo owners oughtn't worry. :)


Thanks for sharing your experiences. I'll again update the Pismo profile, noting that it is designed to function in closed lid mode, although it may overheat due to a G4 upgrade or high ambient temperatures, in which case opening the lid should improve cooling.


Tiger on 500 MHz iMacs Is Great

From Frank Powell:

I have one of those 500 MHz slot loaders but I loaded "Tiger" on it and it works great!

Don't know what to do with it, but it's fun to play with from time.

Frank Powell


I have a 400 MHz ruby iMac (my favorite color) with 512 MB of RAM next to me. I have a couple external drives connected to it so I can readily boot into Mac OS 9, 10.2, 10.3, or 10.4 to do things like compare YouTube performance with different versions of the Mac OS, different resolutions and bit depths, and different browsers, among other things. (Those external drives are also quite a bit faster than what's inside the iMac's case.)

Another thing I do is rip choir CDs to iTunes on the iMac and have it run them on a loop to familiarize myself with the music - no drain of power on my G4, no problem finding and deleting tracks afterwards, and built-in stereo speakers.

I also have a 450 MHz or 500 MHz indigo iMac, which my youngest son is using to finish up his senior year of high school. With a 512 MB upgrade, they run pretty decently under Tiger.


G3 iMacs in a 2008 classroomiMac DVs in Action

From Micah Seymour:

Just read your retrospective on the iMac DV. To many it would bring back memories, and it does for me as well. Memories of this morning....

Here's one of my current labs in action. 25 iMac DV 500 MHz machines all running Tiger.


What are 6-to-8-year-old Macs to the modern school? And it gets worse - at the school where my wife tutors, there are three Macs in the room: a great white eMac (2002-2005), an indigo iMac (circa 2001), and a Bondi blue iMac (1998). I don't know what's in the rest of the classrooms or whether the school has a computer lab, but our children are rarely exposed to up-to-date technology in school. (Remember film strips, 16mm projectors, and early video recorders? I experienced them all.) I understand that schools like to get all the mileage they can out of their computing dollars, and I'm glad you have Tiger running on your, but a lot kids are going to grow up thinking Macs have small screens and a quaint operating system from the 1990s.

A lot of us use low-end Macs by choice. Too many students don't have that option.

(I hope it's okay to post the photo with your letter in the mailbag. I have fuzzed out the two faces that might be recognized.)


We're a rural K-12 unit district (all grades levels in one "big" school). We have a lab of 20 PPC Mini's with 19" LCDs (HS business lab), a lab of 25 eMacs (JH lab), and the elementary lab pictured. I've also got at least an iMac and an eMac in every classroom, and the teachers all have either a 12" iBook or a MacBook (teacher's get a new machine every three years, so I'm about to have a bunch of iBooks that I'll have the terrible problem of figuring out what to do with ;) I've used your site extensively to figure out what I can and can't do with the hardware. So thanks for that.

For me, the lack of processing power rarely hampers my ability to teach. About the only thing I can't teach that I'd like to is some video editing via iMovie. Most of our necessary software is web-based, and I recently switched the district from Office X to Google Docs via Google Apps for Schools for our productivity suite. The teacher's still have a choice of Office 2004 or Google Docs, but most of them have switched to Google Docs.

All that said, I cannot wait to get my hands on my 25 seat mobile MacBook lab next fall. It's doesn't do much for the screen size problem, but it will be nice to get them computers that are as sexy as their iPods.

As for the picture, please post away, I'll show my students that their lab is "famous" in the retro Mac world.

Micah Seymour


I'm glad we're helping you get the most out of the old Macs - that was the goal when I started this 11 years ago. The low end has moved, but it will always be with us.

Those 13.3" 1280 x 800 MacBook screens should be a nice step up from 1024 x 768 on G3 iMacs - and shows nearly as much as 1280 x 960 on those honking big eMacs.

Look for this in Friday's mailbag.


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Dan Knight has been publishing Low End Mac since April 1997. Mailbag columns come from email responses to his Mac Musings, Mac Daniel, Online Tech Journal, and other columns on the site.

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