Determine cache size and rotation speed

Lifeguard does not appear to be able to read cache size and rotation speed for WDC drives.  I’m mainly concerned with Black drives.  Does WDC have a utility to determine this data?

I looked at the trial version of HDTune, but rotation speed was blank and I could not find any screen which listed cache.

Speccy gives heads, cylinders, tracks, and sectors, but I don’t see how that could translate to cache or rotation.  If someone has a formula to determine number and size of platters from that, I’d love to know.

I have already told you how to answer most of your questions (in your other thread), but for reasons only known to yourself, you have decided not to provide the information that I requested.

I once posted a photo of a drive label in this very forum.  The moderator immediately deleted it and informed me that photos containing serial numbers must not be posted here.

I told you about the WDC warranty status.

That URL you provided includes your sentence “I’m not certain about this, though,” and then “I was wrong [regarding the previous assumption],” so the part about heads translating to platters is not definitive.  And your stated logic requires knowing the rotation speed WHICH WAS BLANKED OUT IN HDTUNE.  And none of this would tell me what the cache size is.

My article clearly explains how to read the number of heads off a HD Tune benchmark graph, with particular reference to WD models, and with appropriate pictorial examples. The statement which you have cherry-picked has been taken out of context. It refers to one unusual Seagate HDD that was the subject of a long thread at Seagate’s old forum. In fact the method that forms the basis of my article was brought to my attention by an end user named Floyd, and I thank him for it. Together we were able to subsequently make sense of the unusual graph, and we did this by dumping Seagate’s firmware. In the end everything became crystal clear, and you would know this if you read the article all the way to the end.

In any case, what is preventing you from uploading your own graphs? There are no serial numbers, so there would be no reason for the moderator not to approve them.

As for rotation speed, if your drive were a genuine Caviar Black, then AIUI it should be reporting its RPM to HD Tune. It’s WD’s Green drives that report an RPM of 0, and that’s because WD obfuscates their performance with their IntelliPower marketing nonsense. Nevertheless, it is still possible to determine their RPM from HD Tune’s read benchmark graph, but you need to understand just a little bit about how drives work.

For example, the speed of the drive in the following example is 7200 RPM:

This can be deduced from the access time graph in a matter of seconds.

The transfer rate curve tells us that the drive is fully stroked, and that it most likely has a data density of 500GB per platter. Therefore it would probably have 2 heads. However, this could be more accurately determined by following the simple procedure in my article.

The numbers on the label and on the PCB all have a special meaning which I would be prepared to explain to you, but once again you have decide that such information is irrelevant. (You can redact the model number before posting the image.) What is clear is that the two model numbers have different family identifiers in the suffix (J37 versus Z3).

Your questions regarding cache can be answered with a reference to the ATA standard. Simply put, the ATA standard provides no way for a drive to report a cache size of 32MB or greater. Therefore such drives report 0 for this parameter. You can determine the actual cache size by examining the SDRAM on the PCB, but this would require some basic skill which you appear not to possess or be willing to exercise.

As for the performance numbers, you are correct, they are not very useful. The following graph should tell you why:

“Speccy gives heads, cylinders, tracks, and sectors”, but these numbers are essentially useless. They bear no relationship to the actual drive geometry.