[Info-vax] Storage is faster than the processor

[Johnny Billquist]

On 2016-01-07 03:54, David Froble wrote:
> Stephen Hoffman wrote:
>>
>> Having storage that is faster than the processors renders more than a
>> few system and application design details obsolete.
>>
>>
>>
>> Non-volatile Storage
>> Implications of the Datacenter's Shifting Center
>>
>> https://queue.acm.org/detail.cfm?id=2874238
>>
>>
>> Ponder what this shift means for OpenVMS and its network and storage
>> I/O stacks, for scheduling, fast path and affinity, the new file
>> system and related.  And for your applications, too.
>>
>> This isn't fiction or future, either.   The HPE 3PAR FC SAN SSD
>> storage arrays are just staggeringly faster than the old MSA gear.
>> And that's before any discussions of PCIe or NVDIMMs.
>>
>>
>
> Well, for sure, it's a faster method for making my head hurt ....
>
> Now, remember, I'm a senile old man, who might have more than a little
> trouble envisioning new methods, regardless ....
>
> I am having a hard time imagining how significantly faster storage I/O
> can affect the things that I do with a computer.  As a simple example, a
> simple operation to get some value, increment it by one, and store it.
> The speed of the I/O has nothing to do with the "work" of adding 1 to
> some value.  This takes a CPU or similar logic.  And the problem only
> gets worse, the more "work" needed done with the data.

I didn't even read the link, but I'd like to point out that your current 
fast CPU is spending most of its life just waiting for something to 
happen. SO, obviously, if you want overall perceived speed to increase, 
it is not the CPU that needs to get faster. It can certainly loop more 
times waiting for anything to happen, but that is not going to make you 
happy.
So obviously, it is the things that the CPU is waiting for that needs to 
speed up. And that is memory, network and disk.

"Simple operation to get some value, increment it by one, and store it" 
is actually in many cases a typical example of the CPU waiting an 
eternity to get something to work on. Getting the value? From where? If 
it is of any relevance it will sooner or later end up on some permanent 
storage. Values just kept in a CPU register is not going to be very useful.

	Johnny