Developer Glenn Anderson has released a utility that he believes will identify third party RAM modules potentially disabled by Apple's recently-released firmware update.

The firmware update disables some third-party RAM modules, MacCentral reports. Anderson claims that RAM modules de-activated by the update have timing settings for the DIMMs that do not conform to Apple's requirements.

"Checking through the developer notes for the models of Mac that are having the problem, CL3 mode is required, so the firmware is just being more strict about this," he told MacCentral.

Anderson has created DIMMCheck, a small utililty designed to report the status of RAM installed in the Mac. If Anderson's research is correct, running DIMMCheck before installing the update will detect if any installed RAM is likely to be disabled by the firmware update.

DIMMCheck is available for free download. Macworld has not yet been able to run extensive tests in order to confirm Anderson's claims.