BAD RAM :(
How to Troubleshoot & Rule Out Ram
Mac OSX, Windows, Photoshop
© 2004-2012 www.gballard.net
COMPLETELY REVISED April 2012
BAD RAM can wreak havoc on our sanity....
Bad Ram will surface as intermittent or total system instability, corruption, disk errors or it may prevent the computer from booting altogether.
In addition to crashing, kernel panics, unexpectedly quitting, Type 1 2 3 errors, corrupted files and disk errors typical symptoms of bad Ram in Photoshop include rows lines patches of bad pixels on screen that also print (the actual file is being corrupted).
If the bad pixel areas are on the monitor, but do not print (the actual file is not corrupted), video card or video-card drivers are prime suspects.
- • A bad cable, bad card, bad switch, bad/misconfigured router, bad repeater, bad termination, bad wiring, bad hard drive, bad controller, bad connections, bad logic board, bad CPU (Altivec) just about anything between your computer and other computers can also cause these symptoms in Photoshop, said Adobe computer engineer Chris Cox.
- • For help with TROUBLESHOOTING Photoshop gballard.net.
• If the corrupt pixels are associated with a network disk, see Adobe's Support Doc. # 322391 adobe.com (another great broken link).
- In essence: Copy the file from the server to your local workstation disk, Open the file from your local disk, Save the file to your local disk, Copy the closed file back to the server never Open or Save Photoshop files across a network.
The BAD RAM problem may be associated with a RAM slot on the board, or with two DIMMs or cards that work okay individually, but conflict when used together.
RAM issues can be very intermittent reseat ram, problem returns days later....
|How To Troubleshoot and Rule Out RAM:
After personally troubleshooting many hardware and software problems I've concluded the best and only reliable way to troubleshoot and rule out RAM is to remove all but one RAM DIMM (or pair of cards if your Mac requires two sticks) try to duplicate the problem off your normal working install.
Swap each DIMM stick card SDRAM with another DIMM leaving only one card or pair of cards installed at any time until all your cards have been ruled out (each over hours/days of testing).
There are Ram testers links below, but removing the Ram and testing, as outlined, is the only definitive way to rule out Ram so don't assume your RAM is good if it boots your machine or passes a software test routine.
|RAM GUIDES TO TROUBLESHOOTING, HOW TO
It is hard to keep up with all the various warnings Apple uses in its machines to warn us of RAM problems, but here are some useful guides and tips.
Here is a how to official APPLE RAM GUIDE-MANUAL TO INSTALLING CONFIGURING REPLACING RAM in the Mac Pro (download PDF) Intel-based Mac computers.
So check to ensure RAM is installed properly, reseat memory cards FB-DIMM, and when ram is malfunctioning, check the Riser A and B boards (what the ram plugs into) for any red led lights. A red light here indicates a problem with the RAM.
RAMrelated boot errors (sounds) breaking glass or musical beeps:
Apple TIL apple.com: 15 tones or breaking glass sounds on boot.
- 1 beep = No RAM installed/detected
- 2 beeps = Incompatible RAM type installed (for example, EDO)
- 3 beeps = No RAM banks passed memory testing
- 4 beeps = Bad checksum for the remainder of the boot ROM
- 5 beeps = Bad checksum for the ROM boot block
RAMrelated boot errors (splash screens):
The boot tones or "builtin memory test failed" splash screen make your case in spades.
If you get the tones or failedmemory splash screens on boot, that's all you need say to make your point for warranty replacement if the 'tech' wants to argue that point with you, find another technician.
|RAM TESTERS how good are RAM testers?
|MEMTEST OS X memtestosx.org was recommended to test RAM memory under Apple OSX.
There is also an Apple HARDWARE TEST built into the OEM Apple Install DVDs that may identify the problem. Again, the Apple hardware tester is not definitive, but may also catch a problem in logic board, processors, video cards, power supply or RAM.
The testers are not definative!
In fact, the only way to RULE OUT RAM is to remove it and test without it - but you may get lucky:
Adobe Photoshop engineer Chris Cox, wrote me (about the RAM testers):
Timing problems are the biggest case that most test programs won't catch.
Yet applications will hit them maybe 1/10,000,000 times which is often enough to cause problems.
"Also, testing programs are not using AltiVec or streaming cachehints which change the memory access patterns.
"Testing programs also do most of their testing linearly through memory which does NOT test rapid page (CAS) changes (which applications sometimes cause)."
by: ©2003 G. BALLARD • www.gballard.net
Note: G. BALLARD prefers a shredding if he is wrong or unclear.
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