Building a computer for compiling and CPU emulation (Re: Building computer)
On Sun, Sep 29, 2013 at 1:59 AM, Stan Hoeppner <stan@hardwarefreak.com> wrote:
> On 9/27/2013 6:03 AM, Joel Rees wrote:
>> On Fri, Sep 27, 2013 at 10:22 AM, Tom H <tomh0665@gmail.com> wrote:
>>> On Thu, Sep 26, 2013 at 7:09 AM, Stan Hoeppner <stan@hardwarefreak.com> wrote:
>>>> On 9/26/2013 5:45 AM, Joel Rees wrote:
>>>>> On Thu, Sep 26, 2013 at 2:05 PM, Stan Hoeppner <stan@hardwarefreak.com> wrote:
>>>>>> On 9/25/2013 12:52 PM, Catherine Gramze wrote:
>>>>>
>>>>> Stan, joking aside, are there any AMD processors you would recommend
>>>>> for doing kernel and driver level Android/ARM development in a VM?
>>>>>
>>>>> How likely would I be to find such a processor in a netbook or laptop?
>>>>
>>>> How likely is one to find a kernel developer doing any real work on a
>>>> laptop? Throwing a netbook into the question is just silly.
>>
>> The reason I ask, Stan, is that I'm preparing to take a class where
>> I'll be studying Super H assembly language programming, writing device
>> drivers for an embedded SH3 running a Linux kernel, and such.
>
> I read everything below but my reply will be brief, so going up top with
> it. Performance options with portables is always limited due to power.
> A few quick points:
>
> 1. If you're going to be compiling anything, cache size trumps clock
> speed. If a smaller cache roughly equivalent CPU clocks more than ~30%
> higher than big_cache CPU it becomes a horse race.
>
> 2. Do not use an in-order CPU, such as the Atom, regardless of clock
> speed. The lack of branch prediction, rename registers, etc, will
> hamstring a compiler.
>
> 3. If you're running a hypervisor, low level support such as AMD-V or
> Intel VT will help.
Okay, ...
>> I'd like to prepare a portable emulation environment for the class,
>> since I know I'll be wanting to do homework when the lab is not
>> available. Renasas points to an SH4 emulator by Kawasaki-san that runs
>> under QEMU, but at times I will likely be debugging the emulator as
>> well as my own code. And I'll be doing a lot of compiles in the
>> emulated system.
>>
>> I'll be biking to the class some days and walking other days, so I'd
>> like a 12 inch screen form factor to fit in my bag and not break my
>> back, which pretty much says netbook. Many netbooks have output for
>> external monitors, which will help at home, at least.
>>
>> At this point, I've been kind of looking at Acer's Aspire (heh) V5-122
>> with an AMD A4-1250 and 4G RAM, or a similar V5 with an AMD A6-1450.
>> I'm trying to figure out whether they support QEMU. If so, I'm
>> thinking the 4-core A6 will be worth the extra 5000 yen, a pair of
>> core for the host OS and I/O, and another core for the emulation
>> environment makes three.
>>
>> I'm also looking at an HP dm1-4400, but the processor there is an AMD
>> E2-1800, which seems to be last year's tech and a little heavier on
>> battery use. It's only two cores, and only 2G RAM in the version at
>> the store where I was looking at it (Sofmap in Umeda -- Osaka), but
>> maybe HP is sturdier than Acer. I need to look at that.
http://en.wikipedia.org/wiki/List_of_AMD_mobile_microprocessors
tells me that AMD A4-1250, AMD A6-1450, and E2-1800 all have AMD-V.
The E2-1800 has a half-Meg L2 cache, but higher speed CPU (1.7GHz).
The A4-1250 has 1 Meg L2 cache but lower speed CPU (1.0 GHz).
The A6-1450 has 2 Meg L2 cache to share between twice the CPUs.
>>[...]
So now my problem is scraping up 55,000 yen +/-.
--
Joel Rees
Be careful where you see conspiracy.
Look first in your own heart.
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