linux - Does lshw list the "factory" speed of a memory module or the effective speed and how to find the former?

I hope I phrased this correctly. lshw
gives:

 description:
            DIMM Synchronous 400 MHz (2.5 ns)
 product: M378B5773CH0-CH9

            vendor: Samsung
 physical id: 0
 slot: DIMM0
 size:
            2GiB
 width: 64 bits
 clock: 400MHz
            (2.5ns)

And
indeed the memory speed is set is set to 800MHz in the BIOS, which I think makes sense
since it is a double rate.

On the other hand,
Googling strongly suggests that to this product number corresponds the PC3-10600 type,
which is 1333MHz, not 800MHz. And this seems to be confirmed in the BIOS, where if I
select Auto for memory bus speed, 1333MHz is selected "based on SPD
settings".

However in the latter case, the
computer does not boot, i.e. the kernel panics, complaining that something attempted to
kill the Idle process.

So, I am I am beginning
to suspect that I have been given defective memory, the technician that installed saw
this, and lowered the bus speed. Is this a
possibility?

NEW
DEVELOPMENT

The suggestions below
have been very helpful, wish I could accept them both. Well, before running the memtest,
I had the idea to reset the bios to its default settings, which I had not done on this
computer. What do you know? Both the bus clock was set to Auto, i.e. 1333MHz and the
computer booted normally, and seems to be able to pass the memtest (didn't let it
finish). Before, I could not even get GRUB to load sometimes, and never the
system.

So although I was paranoid about being
scammed, it was some setting that the retailer en(dis)abled that
caused the crashes. What it was, and why they had changed it will probably remain a
mystery, since the days when I could understand HALF the options in my BIOS are long
gone. :-)

I will post back if there is any more
instability. Many thanks.