Aaron Spink (aaronspink.delete@this.notearthlink.net) on April 18, 2019 2:32 pm wrote:
> anon (spam.delete.delete.delete@this.this.this.spam.com) on April 18, 2019 12:07 pm wrote:
> > Yes, we all agree that any NAND will get stupidly high sequential
> > read speeds, higher than the controller and interfae can handle.
> > This does not make the downsides of QLC disappear.
> >
> For this application, I'm not convinced that QLC downsides are at all relevant.
>

And I'm not convinced that the upsides (price) exist.

> > Are you sure they'll be able to get 1 TB QLC for 20$ a year or so before launch? Judging by current
> > prices something would have to go horribly wrong for NAND manufacturers to offer such a deal.
> >
> On a multi-year capacity contract, its possible. Manufacturers are close to transitioning
> to smaller processes and higher stack counts which will push pricing down. Current market
> pricing would be ~$35-40 which should drop with the next node and stack size.
>

Same argument with HAMR and other advancements and multi-year contracts for HDDs.

>
> > I would've said 250-500 GB NAND + 4 TB HDD. Do the math with that and I've also used
> > higher prices for QLC. I'll believe in 20$ per TB when I see it. If your premise is
> > that the price of NAND will be lower than any HDD of the same capacity then the workload
> > doesn't even factor into it anymore. I'm just not willing to buy your premise.
> >
> HDD only get a cost advantage when they are pushing max capacity. 14 TB+ drives will have
> a cost advantage but that advantage doesn't scale down to realistic sizes for a console.
> When you start getting into 4TB drives, you are pretty much already at or below the cost floor
> for HDDs. And QLC/OLC are coming on pretty fast with significant ramifications.
>

I can buy a 3-4 TB HDD for 80$ right now easily. HDDs beat your best case scenario with current pricing and no multi-year contract. So unless Sony manages to pay more than I'd have to HDDs are still definitely cheaper than QLC.

> > Also datacenter workloads are quite different. You'd expect all data to be accessed. Unless someone
> > comes up with a >500 GB game and I really doubt that the working set will never exceed that size and
> > a 500 GB cache will work quite well. Realistically I'd expect much less. Apart from a few outliers it's
> > mostly around 50 GB now, so 100-150, maybe 200 for a few sound reasonable. That's 3-5 games fully cached
> > on 500 GB. Seems good enough to me. Again, that's quite different from a datacenter workload.
> >
> I'm talking about consumer workloads with caching, not datacenter workloads. It does a pretty bad job.
>

I'm pretty sure you wrote datacenter.

> And there are multiple games in the ~100GB range at the moment with many more coming. I just
> don't see them doing less than 1TB of flash storage nor do I foresee them spending the complexity
> or resources for caching. If they support HDDs at all, it will be over USB.
>

Name 3 games >100 GB on the PS4. Then look at how many are under 70 or even under 50 GB.
Yes, some ridiculous things exist. No, they are not the norm.