DDR2 backwards compatibility question

[GT]

Is new, fast DDR2 800 backwards compatible with slower DDR2 533 and 667
motherboards (as DDR and previous generations were)?

Basically, is the 800 the 'upper limit' and will it be happy running at 667
or is the 800 a specification and fixed? I am expecting people to say that
its the maximum speed tested, but worth asking this before buying!

I have an ASRock 4CoreDual-VSTA
(http://www.asrock.com/mb/overview.asp?Model=4CoreDual-VSTA), which takes up
to 2GB of 667 DDR2, but I have just found some cheap DDR2 800 sticks. Can
anyone see any compatibility issues with installing 2 matched sticks of the
following in the above board?:

PC2-6400 DDR2 800MHz
CAS 4-4-4-12
GeIL OC Certified FBGA 64MB X 8 or 128MB x 8 DDR2 Chips
Working Voltage : 1.9-2.3V
240pin, Un-buffered DDR2 DIMM

Thanks,
GT

 

[GT]

Is new, fast DDR2 800 backwards compatible with slower DDR2 533 and 667
motherboards (as DDR and previous generations were)?

Basically, is the 800 the 'upper limit' and will it be happy running at
667 or is the 800 a specification and fixed? I am expecting people to say
that its the maximum speed tested, but worth asking this before buying!

I have an ASRock 4CoreDual-VSTA
(http://www.asrock.com/mb/overview.asp?Model=4CoreDual-VSTA), which takes
up to 2GB of 667 DDR2, but I have just found some cheap DDR2 800 sticks.
Can anyone see any compatibility issues with installing 2 matched sticks
of the following in the above board?:

PC2-6400 DDR2 800MHz
CAS 4-4-4-12
GeIL OC Certified FBGA 64MB X 8 or 128MB x 8 DDR2 Chips
Working Voltage : 1.9-2.3V
240pin, Un-buffered DDR2 DIMM

And... is the above 4-4-4-12 be actually/noticably faster than cheaper CL5
sticks in general windows work or gaming?

 

[Paul]

And... is the above 4-4-4-12 be actually/noticably faster than cheaper CL5
sticks in general windows work or gaming?

DDR2 is backward compatible. A DDR2-800 stick, can run at DDR2-667 or
DDR2-533. The CAS won't make that much difference.

Paul