Re: [gentoo-user] processor speed

[R0b0t1]

Hello, I apologize for the tangents.

The only on-topic comments I can offer are that: yes, those parts seem
to be usable with Gentoo, whereas similarly old parts a decade ago
were not; and, I have been looking for a low power server setup and
would appreciate if you could communicate your ultimate part
selection.

Also that a $350-$400 CPU seems to be more than sufficient. My
i7-4770K is still very capable and that I look forward to some day
using a multisocket system with very nice Xeons (or the AMD
equivalent, if it becomes competitive).

On Mon, Aug 28, 2017 at 7:48 PM, Rich Freeman <rich0@g.o> wrote:
> On Mon, Aug 28, 2017 at 8:29 PM, wabe <wabenbau@×××××.com> wrote:
>> Rich Freeman <rich0@g.o> wrote:
>>
>>> On Mon, Aug 28, 2017 at 5:22 PM, wabe <wabenbau@×××××.com> wrote:
>>> >
>>> > I'm using an AMD Phenom(tm) II X4 965 Processor. I bought it six or
>>> > seven years ago when it was brand-new. It still works to my
>>> > satisfaction. But of course recent CPUs (for example AMD Ryzen) are
>>> > much faster. Therefore I wanna buy an AMD Threadripper next year.
>>> > This should be an enormous speedup. :-)
>>>
>>> Having just upgraded one of those to a Ryzen 5 1600 I can tell you
>>> that besides tripling your kernel build speeds, it will also sound
>>> less like a hair dryer and make your room feel less like it has a
>>> space heater inside.
>>
>>
>> I'm not sure what TDP my Phenoms have (95W or 125W). The TDP of the
>> 1950X is rated at 180W. But this is for all cores running at full load.
>> So the effective heat output over time should be lower than with my old
>> CPUs.
>
> Your old CPU has a TDP of 140W.  I forget which model exactly I had
> but I think its TDP was 195W.
>
> Sure, the 1950X is going to pull quite a bit of power, but my 1600
> only pulls 65W when going full tilt.  It is a very noticeable
> difference.  I suspect my old CPU probably used a good portion of that
> at idle.
>
>>
>> Because of the high price for the whole machine (board, ram, cpu...)
>> I will replace my two PCs (one Windoze and one Gentoo) with a single
>> machine. However I have some concerns regarding dualboot. I would
>> prefer NVMe SSDs but I think it may be better to use eSATA disks. Then
>> I easily can switch the disks and it should be impossible that one OS
>> can compromise the other.
>
> Seems like eSATA is harder to find these days.  USB3 seems to be the
> way things are going.  However, that works just fine.
>

For a small amount of time you could find combination eSATA/USB 3
connectors. I lament their demise.


Something to be aware of is that, in general, USB hubs will operate at
the speed of the slowest device connected. This is problematic because
a lot of motherboards and cases are such that a mouse and keyboard are
on the same hub that you would use at the front of your case. Mice and
keyboards are typically USB 1.1 devices.

For USB 1.1 to USB 2, there is *supposed to be* one or more
transaction translators that take USB 1.1 data and retransmit it at
USB 2 speeds. Some hubs don't seem to implement this properly and
connecting a USB 1.1 device slows the entire bus down to USB 1.1
speeds. Even if a transaction translator is present, the bus will
remain busy for the entire USB 1.1 communication time taken by the
device, slowing everything down.

For USB 2 to USB 3, there is no conversion performed. This leads to a
situation contrary to what most people would expect - multiple USB 2
devices can not take advantage of more than the default USB 2
bandwidth. USB 2 connections to a USB 3 hub simply do not use the USB
3 data lines, which are necessary for the increased bandwidth.

Additionally, some hubs will downgrade USB 3 links to USB 2 speeds if
a USB 2 device is present for unknown reasons. This might be because
of the issue in the second paragraph, e.g. the requirement to wait for
USB 2 transmissions. Reading the specification as to whether this was
allowed behavior didn't make clarify anything to me.

Regardless, the result is that if you plug a USB 1.1 device into a USB
3 hub you might slow your file transfers down by an order of magnitude
or more. This is exactly what I experienced that led me to researching
this issue.

> On my motherboard at least the PCI-based NVMe came at the cost of
> disabling one of the x16 slots, and the SATA-based one came at the
> cost of disabling one of the SATA ports.  So, no PCI-based NVMe for me
> as I have an 8x card in addition to my graphics card.
>
> They really need to make more flexible slots as I believe that the
> slots themselves are electrically compatible - that is you can shove a
> 16x card in a 1x slot as long as you eliminate the plastic that blocks
> this from happening.  Granted, I wouldn't want to put my LSI card in a
> 1x slot - it would be nicer if they had a 2x or 4x slot in there, but
> I realize that 1x and 16x seems to be where all the demand is.
>

This is true. Unless the OS on the graphics card is making assumptions
it shouldn't be, it should be able to run with any number of lanes. A
lot of PCIe bridges can only allocate lanes in multiples of 2, 4, 8,
and 16, however.

Based on some of my reading however the choices your motherboard
manufacturer made were made because non-server Intel (and AMD?) parts
have a very limited number of PCIe and other high speed interfaces
available. I would need to double check, but the configurations you
want might only be possible with server parts.

>>
>> Hopefully the price for RAM will drop before I buy the new rig. It's
>> incredible high at the moment.
>>
>
> Yeah, the best price I could find as $99 for 8GB of DDR4 ECC, and only
> at 2400.  Not much of a consumer market for ECC.
>

There was recently a price fixing class action settlement for DDR2
RAM. I hope there is another for modern RAM, as you can plot the price
against that natural disaster where the main manufacturing facilities
were and see that it never went back down afterwards.

But I suppose my greed is getting to me. Our betters have decided what
the price should be, and I should be happy that I can afford RAM and a
nice computer to use.

R0b0t1.