Re: AMD64-based laptops from HP/Compaq are crippled

From: Robert Klute (news_at_klute.us)
Date: 07/05/05 

Date: Tue, 05 Jul 2005 06:55:04 GMT

On Mon, 04 Jul 2005 23:19:07 -0700, alex goldman <hello@spamm.er> wrote:

>Robert Klute wrote:
>
>> On Mon, 04 Jul 2005 20:46:58 -0700, alex goldman <hello@spamm.er> wrote:
>>
>>>I've been researching my next laptop purchase, and whether it will run
>>>Linux, and completely accidentally stumbled upon an alarming issue that
>>>people need to be more aware about.
>>>
>>>Apparently (and if my understanding is correct), HP/Compaq disables
>>>dual-channel memory access in Socket 939 motherboards, making CPU <-> RAM
>>>communication slower, and overall performance less than what people would
>>>expect when buying a system with the outward characteristics of what they
>>>think they are getting.
>>>
>>>http://zv6000forums.com/viewtopic.php?t=148
>>
>> The laptops use the Turion chip.
>
>Wrong. _Some_ of the laptops use the Turion chip (quite few as of this
>writing, actually).

The zv6000, the laptop under discussion here and in the forum you
referenced, uses the Turion chip.

>Regardless ...
>
>> According to AMD, the Turion's
>> integrated memory controller can use PC1600, PC2100, PC2700 or PC3200
>> unbuffered DDR SO-DIMMs and has a maximum throughput of 3.2 GB/s.
>
>Do you understand how dual-channel access works? You have 3.2 GB/s per
>memory module, i.e. up to 6.4 GB/s. Dual-channel access is more, not less,
>important when slow memory is used.

NO, the Turion's memory controller is 64-bit and limited to a max of
3.2GB/s. Dual channel won't help. Read the specs. Here is the
executive's graphic for you:
http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_12651_12663,00.html

>
>> So, explain to me what engineering in dual channel support is going to
>> buy you. BTW, does any vendor manufacture dual channel compatible
>> SO-DIMMs?
>
>There is something you have in common with the NoNoBadDog

Relevant Pages

  • Re: AMD64-based laptops from HP/Compaq are crippled
    ... does any vendor manufacture dual channel compatible ... 939 pin processor which could have supported dual channel memory if they ... All laptops in this range have two DIMM sockets so ... native Linux driver. ...
    (comp.os.linux.portable)
  • Re: AMD64-based laptops from HP/Compaq are crippled
    ... > The laptops use the Turion chip. ... Do you understand how dual-channel access works? ... memory module, i.e. up to 6.4 GB/s. Dual-channel access is more, not less, ...
    (comp.os.linux.portable)