From: Arne Vajhøj on
On 12-01-2010 14:08, Lew wrote:
> On Jan 12, 11:16 am, Wojtek<nowh...(a)a.com> wrote:
>> Arne Vajh�j wrote :
>>> On 11-01-2010 17:09, Maarten Bodewes wrote:
>>>> Arne Vajh�j wrote:
>>>>> BTW, even long would be too small for indexes if Java
>>>>> will be used after 2074, but somehow I doubt that would
>>>>> be the case. And besides we do not have the verylong datatype
>>>>> yet.
>>>> You are expecting memory sizes of 9,223,372,036,854,775,807 bytes????
>>>> That's 9,223 PETA bytes. Hmm, weird, may happen. But it is certainly
>>>> rather large.
>>
>>> In 2074 ? Yes !
>>
>> I am curious. Just what WOULD need such a large index? Every sand grain
>> on earth? Every star in every galaxy in the universe?
>
> Where will you store the array? Either you have a crapload of RAM
> (one bit per atom storage density?) or the largest-capacity storage
> device ever invented (one bit per atom storage density?).
>
> What's the average retrieval latency? Even at one bit per atom
> storage density, it must take even a light beam noticeable time to
> reach the further reaches of the storage device; anything slower like
> a semiconductor must take a really long time.
>
> A silicon crystal lattice has a lattice spacing of just over half a
> nanometer, or 5.4 x 10^-10 m. A three-dimensional storage medium for
> a 9 x 10^18-element array would hold juar over 2 x 10^6 elements to
> the side. An average access would be halfway in each dimension, or
> 10^6 elements, which in a silicon lattice is about 5.4 x 10-4 m, times
> three for a total traversal distance of about 1.6 x 10^-3 m. Each
> way. For a round trip slightly over 3 x 10^-3 m. A light beam
> travels that in 0.1 microseconds (10^-7 s). That's about 200 clock
> cycles of latency on a modern processor, far more on the future
> processors of 2074.

With correction:
>Drat! Mixed up my CGS and MKS. That's 10-5 s, or 10 microseconds.

Neither looks correct to me.

s = 3 x 10^-3 m
v = 3 x 10^8 m/s
=>
t = s/v = 1 x 10^-11 s

Arne

From: Lew on
Lew wrote:
>> Drat! Mixed up my CGS and MKS. That's 10-5 s, or 10 microseconds.

Arne Vajhøj wrote:
> Neither looks correct to me.
>
> s = 3 x 10^-3 m
> v = 3 x 10^8 m/s
> =>
> t = s/v = 1 x 10^-11 s

Sigh.

You are, of course, absolutely correct.

--
Lew
From: RedGrittyBrick on

Arne Vajhøj wrote:
> On 12-01-2010 11:16, Wojtek wrote:
>> Arne Vajhøj wrote :
>>> On 11-01-2010 17:09, Maarten Bodewes wrote:
>>>> Arne Vajhøj wrote:
>>>>> BTW, even long would be too small for indexes if Java
>>>>> will be used after 2074, but somehow I doubt that would
>>>>> be the case. And besides we do not have the verylong datatype
>>>>> yet.
>>>>>
>>>> You are expecting memory sizes of 9,223,372,036,854,775,807 bytes????
>>>>
>>>> That's 9,223 PETA bytes. Hmm, weird, may happen. But it is certainly
>>>> rather large.
>>>
>>> In 2074 ? Yes !
>>
>> I am curious. Just what WOULD need such a large index? Every sand grain
>> on earth? Every star in every galaxy in the universe?
>
> I don't know.
>
> What I do know is that several times during the last 50 years
> somebody has said that you will never need more than X memory.
> And they have been wrong every time.
>
> I think it is most logical to assume that trend will continue
> and that we indeed will find something to use such huge
> address spaces for.

And if we don't, Microsoft's Office team will ;-)

--
RGB
From: Arne Vajhøj on
On 19-01-2010 04:36, RedGrittyBrick wrote:
>
> Arne Vajhøj wrote:
>> On 12-01-2010 11:16, Wojtek wrote:
>>> Arne Vajhøj wrote :
>>>> On 11-01-2010 17:09, Maarten Bodewes wrote:
>>>>> Arne Vajhøj wrote:
>>>>>> BTW, even long would be too small for indexes if Java
>>>>>> will be used after 2074, but somehow I doubt that would
>>>>>> be the case. And besides we do not have the verylong datatype
>>>>>> yet.
>>>>>>
>>>>> You are expecting memory sizes of 9,223,372,036,854,775,807 bytes????
>>>>>
>>>>> That's 9,223 PETA bytes. Hmm, weird, may happen. But it is certainly
>>>>> rather large.
>>>>
>>>> In 2074 ? Yes !
>>>
>>> I am curious. Just what WOULD need such a large index? Every sand grain
>>> on earth? Every star in every galaxy in the universe?
>>
>> I don't know.
>>
>> What I do know is that several times during the last 50 years
>> somebody has said that you will never need more than X memory.
>> And they have been wrong every time.
>>
>> I think it is most logical to assume that trend will continue
>> and that we indeed will find something to use such huge
>> address spaces for.
>
> And if we don't, Microsoft's Office team will ;-)

It seems to be a rather universal rule, that if the HW guys
can produce some new HW that are N times faster/bigger then
us SW guys will find a way to make our apps require the same
N times more resources.

Arne