Please help me choose Memory for AMD64

[Synapse Syndrome]

I need to get a new PC in a *hurry* and my workload doesn't give me the time
to research this properly. This PC is to be used for architectural CAD and
3D modelling with quite a bit of Photoshop and DTP work as well. No games
or overclocking.

I've decided on these components for price/performance and necessary
features:

AMD Athlon64 3400+
Asus K8N-E Deluxe or K8V Deluxe / K8V SE Deluxe
3Dlabs Wildcat VP880 Pro

I'm not sure whether to go for the nForce-250GB or K8T800 chipset but I am
tending towards the nForce unless anybody can tell me the advantages of the
other.

But what really has me stumped is what memory to get. I need this new
computer as my current one can't smoothly handle the complex CAD models with
a lot of Geometry in OpenGL windows. It slows down too much for me to work
effectively. So I guess I need some pretty fast memory.

Should I get ECC memory? Matched pair? What brand? How low should I go
with the latency with price/performance and the rest of my system in mind
and the fact that I am not interested in overclocking or games.

Thanks for your help.

ss.

 

[GSV Three Minds in a Can]

I need to get a new PC in a *hurry* and my workload doesn't give me the time
to research this properly. This PC is to be used for architectural CAD and
3D modelling with quite a bit of Photoshop and DTP work as well. No games
or overclocking.

I've decided on these components for price/performance and necessary
features:

AMD Athlon64 3400+
Asus K8N-E Deluxe or K8V Deluxe / K8V SE Deluxe
3Dlabs Wildcat VP880 Pro

I'm not sure whether to go for the nForce-250GB or K8T800 chipset but I am
tending towards the nForce unless anybody can tell me the advantages of the
other.

But what really has me stumped is what memory to get. I need this new
computer as my current one can't smoothly handle the complex CAD models with
a lot of Geometry in OpenGL windows. It slows down too much for me to work
effectively. So I guess I need some pretty fast memory.

Should I get ECC memory? Matched pair? What brand? How low should I go
with the latency with price/performance and the rest of my system in mind
and the fact that I am not interested in overclocking or games.

Hmm, sounds to me that what you really want is a dual (or more) Cpu
=workstation=, based around AMD Opteron (or Intel Xeon) processors. Last
time I looked 'architectural CAD' was just the sort of thing these were
aimed at. If you really want to build it yourself there are now some
Opteron Dual processor boards available on the end user market.

'Matched pair' memory is a ripoff, IMO. Buy two sticks from the same
source and you get a matched pair, close as the motherboard should care.
For dual CPU systems you will almost certainly need registered memory.
ECC .. optional, unless the board requires it. I haven't used it for
years .. most boards don't even support it.

 

[Paul Hopwood]

I need to get a new PC in a *hurry* and my workload doesn't give me the time
to research this properly. This PC is to be used for architectural CAD and
3D modelling with quite a bit of Photoshop and DTP work as well. No games
or overclocking.

If you're that pushed for time and the machine is critical you might
be better buying pre-assembled or even a branded workstation.

But what really has me stumped is what memory to get. I need this new
computer as my current one can't smoothly handle the complex CAD models with
a lot of Geometry in OpenGL windows. It slows down too much for me to work
effectively. So I guess I need some pretty fast memory.

It is unlikely to be RAM speed which is slowing you down but rather a
lack of it, or performance bottlenecks elsewhere.

The amount of memory is more critical than speed. While the
difference between the slowest PC2100 DDR266 and the fastest PC5300
DDR2-667 would be extreme in benchmarks it is much less apparent in
real applications.

Should I get ECC memory?

ECC adds reliability, not performance. It's used in business-critical
applications such as servers and high-end workstations to ensure
integrity of the data but is marginally slower than non-ECC.

Matched pair?

A complete rip-off. All "matched pair" effectively means is the
manufacturer has packaged them in twos as they've come off the
production line. Purchasing two identical part numbers at the same
time will have the same result without the price premium.

What brand? How low should I go
with the latency with price/performance and the rest of my system in mind
and the fact that I am not interested in overclocking or games.

For business applications I'd opt for something reliable and
guaranteed such as Crucial or Kingston. If you're more concerned with
performance then Corsair or OCZ are favourites, but in real terms even
the most "extreme" memory has little on overall performance.

--

 

[General Schvantzkoph]

Hmm, sounds to me that what you really want is a dual (or more) Cpu
=workstation=, based around AMD Opteron (or Intel Xeon) processors. Last
time I looked 'architectural CAD' was just the sort of thing these were
aimed at. If you really want to build it yourself there are now some
Opteron Dual processor boards available on the end user market.

'Matched pair' memory is a ripoff, IMO. Buy two sticks from the same
source and you get a matched pair, close as the motherboard should care.
For dual CPU systems you will almost certainly need registered memory.
ECC .. optional, unless the board requires it. I haven't used it for
years .. most boards don't even support it.

I don't think Athlon 64 motherboards support ECC, Opteron boards do. ECC
is always a good option if the motherboard supports it. Crucial is my
brand of choice.

 

[Synapse Syndrome]

Hmm, sounds to me that what you really want is a dual (or more) Cpu
=workstation=, based around AMD Opteron (or Intel Xeon) processors. Last
time I looked 'architectural CAD' was just the sort of thing these were
aimed at. If you really want to build it yourself there are now some
Opteron Dual processor boards available on the end user market.

I wish! But I have to eat and pay the rent too.

Well when I'm fully qualified I will most likely work on machines like that
in the London firms, but at the moment I use a PowerMac G4 at work and this
for my home computer to complete my studies.

'Matched pair' memory is a ripoff, IMO. Buy two sticks from the same
source and you get a matched pair, close as the motherboard should care.

Yeah I thought so. They cost so much more the money would be better used
towards a faster processor.

For dual CPU systems you will almost certainly need registered memory.
ECC .. optional, unless the board requires it. I haven't used it for
years .. most boards don't even support it.

The Asus boards I mentioned do.

ss.

 

[Synapse Syndrome]

I don't think Athlon 64 motherboards support ECC, Opteron boards do. ECC
is always a good option if the motherboard supports it. Crucial is my
brand of choice.

The Asus boards do take ECC memory, but only un-buffered. Should I choose
this? I can only find registered ECC RAM.

ss.

 

[Synapse Syndrome]

If you're that pushed for time and the machine is critical you might
be better buying pre-assembled or even a branded workstation.

I cannot afford this, and I'd prefer to build my own anyway.

It is unlikely to be RAM speed which is slowing you down but rather a
lack of it, or performance bottlenecks elsewhere.

It's really the processor, but I have been told that certain programs I use
could benefit from faster RAM.

The amount of memory is more critical than speed. While the
difference between the slowest PC2100 DDR266 and the fastest PC5300
DDR2-667 would be extreme in benchmarks it is much less apparent in
real applications.
Okay.


ECC adds reliability, not performance. It's used in business-critical
applications such as servers and high-end workstations to ensure
integrity of the data but is marginally slower than non-ECC.

I've heard that ECC would be needed if I have 3 or more RAM modules, which I
may have later on. The boards I have chosen have 3 slots I think.

A complete rip-off. All "matched pair" effectively means is the
manufacturer has packaged them in twos as they've come off the
production line. Purchasing two identical part numbers at the same
time will have the same result without the price premium.

I've ruled matched pair out. I'll use the money elsewhere.

For business applications I'd opt for something reliable and
guaranteed such as Crucial or Kingston. If you're more concerned with
performance then Corsair or OCZ are favourites, but in real terms even
the most "extreme" memory has little on overall performance.

So 2.5 CAS would be okay price.performance wise? Sounds good.

ss.

 

[Tim Auton]

Should I get ECC memory? Matched pair? What brand? How low should I go
with the latency with price/performance and the rest of my system in mind
and the fact that I am not interested in overclocking or games.

Tricky question, as what you need is a kick-ass workstation yet you
also need VFM.

ECC does nothing for performance. If anything, it hurts performance.
It certainly hurts your pocket. For working on expensive stuff (where
errors can cost money or lives) it's worth it, for learning the tools
of the trade it's an expensive luxury.

I'd select a RAM frequency that was a good match for the CPU and get
the lowest latency I could find.

As for GFX card, not all 3D CAD stuff takes full advantage of all
cards, so check before you buy.


Tim

 

[CBFalconer]

I need to get a new PC in a *hurry* and my workload doesn't give
me the time to research this properly. This PC is to be used for
architectural CAD and 3D modelling with quite a bit of Photoshop
and DTP work as well. No games or overclocking.
.... snip ...

Should I get ECC memory? Matched pair? What brand? How low

.... snip ...

Definitely ECC. For architectural work you are responsible for
the quality of your work, and a fouled result could cost you and
your firm everything in liability, not to mention the guilt
feelings. See the 'Error Correction' thread in this newsgroup.
[1] Be afraid, very afraid. If something evil occurs the
existence of this exchange will even demonstrate willful ignoring
of cheap preventatives, and make the situation worse. OTOH, use
of ECC demonstrates proper care and diligence, at least in one
aspect.

[1] alt.comp.hardware, with crosspostings. If you have problems
finding the thread with google chase postings with my name as
poster. There is a link for that on my homepage.

 

[Daniel James]

AMD Athlon64 3400+
Asus K8N-E Deluxe or K8V Deluxe / K8V SE Deluxe [snip]

I'm not sure whether to go for the nForce-250GB or K8T800 chipset but
I am tending towards the nForce unless anybody can tell me the
advantages of the other.

Some people dislike VIA chipsets on principle. They're not really any less
good than any other -- though I'd always pick an intel chipset if I were
using an intel CPU.

In this case -- Socket 754 Athlon64 -- the nForce chipset supports DDR RAM
but the KT800 doesn't. If memory speed is of importance (and I really don't
have any feel for how important it will turn out to be for your intended
use) that may be a factor.

If memory speed really is an issue then you should be aware that the Socket
939 Athlon64s are the only ones that support dual-channel RAM -- but
they're a rather different cricket match as far as price is concerned.

I need this new computer as my current one can't smoothly handle the
complex CAD models with a lot of Geometry in OpenGL windows. It slows
down too much for me to work effectively. So I guess I need some
pretty fast memory.

It may just be that you need *more* memory. What's your current system? How
big are your models? Does the system spend all its time swapping when you
work with these large models (is the hard disk light almost continuously
on)?

Should I get ECC memory?

Other things being equal, always get ECC memory. Other things aren't equal,
though, as ECC memory is very slightly slower than non-ECC and costs about
20-25% more. You'll also find that choosing ECC memory reduces your options
for motherboards.

For a work machine I'd say always get ECC. For a games-only machine I'd say
avoid it. For anything else it's a personal choice.

Matched pair?

Matched pairs of memory really only matter with dual-channel memory
systems, when the CPU/chipsets require the two memory modules to have the
same characteristics (timings, etc.). For a Socket754 A64 there's no point
as you won't have dual channels.

Even so, even un-paired memories should give no problems on a dual-channel
system as long as you have good-quality memories from the same maunfacturer
and aren't pushing the limits of overclocking. Paying extra for
matched/paired memory can be seen as an insurance policy against odd timing
problems in extreme circumstances, and it can be seen as a rip-off by
manufacturers.

The more I think about this ... and assuming memory speed really is an
important factor for you ... the more I think that in your case you might
actually be better advised to go for an intel solution - say a P4
Northwood. Modern P4 boards generally all support dual-channel DDR memory
which you won't get with Socket754 and the hyperthreading feature of the
CPU may be able to speed up the complex calculations needed for your 3D
models. It depends rather on how much of the work can be passed off onto
the graphics card (and that depends as much on your CAD software as on the
card you choose).

A 3.4GHz Northwood will cost roughly the same as an A64 3400 (perhaps a few
pounds more) and a motherboard like the P4P800 (or P4C800 if you go for ECC
RAM) will be similar to the K8N-E (or perhaps a few pounds less). I really
can't say how the performance will compare for your uses.

Just a thought.

Cheers,
Daniel.

 

[Tony Houghton]

In <[email protected]>,

In this case -- Socket 754 Athlon64 -- the nForce chipset supports DDR RAM
but the KT800 doesn't. If memory speed is of importance (and I really don't
have any feel for how important it will turn out to be for your intended
use) that may be a factor.

In what way doesn't the KT800 support DDR RAM? Do you mean it doesn't
use the falling edge of the clock cycle and runs it on the rising edge
only as if it were SDRAM?

Also I've forgotten how Intel get away with doubling their quoted FSB
speeds compared to AMDs. What's the reason for that again?

 

[Paul Hopwood]

I cannot afford this, and I'd prefer to build my own anyway.

You are aware that building your own PC costs you MORE than buying a
pre-assembled PC?

It's really the processor, but I have been told that certain programs I use
could benefit from faster RAM.

Highly unlikely. More RAM rather than faster RAM is likely to be of
more benefit. If you're building to a budget you'd be better getting
larger but slower modules are than spending more on faster parts and
having to skip on capacity.

I've heard that ECC would be needed if I have 3 or more RAM modules, which I
may have later on. The boards I have chosen have 3 slots I think.

Untrue. ECC or non-ECC has no bearing on the number of modules you
can fit. Most desktop motherboards don't support ECC RAM so it will
either operate as non-ECC or, possibly, not at all.


--

 

[GSV Three Minds in a Can]

You are aware that building your own PC costs you MORE than buying a
pre-assembled PC?

That turns out not to be the case for multi-CPU workstations (which was
what was under discussion) since there are not enough OEM box-shifters
to bring the price down, so HP et-al think they can gouge you.

 

[General Schvantzkoph]

You are aware that building your own PC costs you MORE than buying a
pre-assembled PC?

That may be true for cheap consumer grade machines but as soon as you get
into workstation and server class boxes the savings over buying from Dell
or someone like them are huge. It cost me $1800 to put together a dual
Xeon server last year (using a SuperMicro motherboard which is as good as
anything Dell or IBM uses). The same configuration from Dell was almost
$2000 more. You can get systems assembled by various online suppliers and
the cost to do that is reasonable. On the server that I built it would
have cost a couple of hundred dollars more which is certainly worth it.
You can also avoid paying for Windows by building it yourself or buying
form a white box guy. Dell will sell you a Linux box but they don't pass
on most of the savings, the price difference is trivial.

 

[Tim Auton]

That turns out not to be the case for multi-CPU workstations (which was
what was under discussion) since there are not enough OEM box-shifters
to bring the price down, so HP et-al think they can gouge you.

They also offer decent support on such boxen.


Tim

 

[kony]

You are aware that building your own PC costs you MORE than buying a
pre-assembled PC?

Not really, if you want to compare prices of discounted/sale
name-brands, then be sure to compare to discounted/sale
individual parts. OEMs _DO_ offer an advantage in bundled
software but most veterin users have little need for all the crap
bundled with OEM boxes except the Window's license itself... and
then we have to consider that many OEM don't even provide the
Windows CD.

Highly unlikely. More RAM rather than faster RAM is likely to be of
more benefit. If you're building to a budget you'd be better getting
larger but slower modules are than spending more on faster parts and
having to skip on capacity.

Essentially this box will be a workstation, so after budget is
determined, and amount of memory needed, the remaining question
is what quality does the budget allow. Generally getting max
performance requires overclocking, regardless of any other
issues, simply because the CPU is spec'd to run on an
industry-standard bus speed. _IF_ chipset and board itself is
known to stabily attain higher clock speed than default, in that
case a memory with higher spec support would be a prudent
purchase. Then again, it's a lot of work for what may only be
5-10% benefit.


Don't be thinking "later on", for machines with large amounts of
memory it is best to buy all of it at once, so you can test that
the modules are not only stable at spec'd speed, but that
multiplies are still stable.

In other words, two modules of brand/type "X" memory might be
fine in any given motherboard, but add a 3rd or 4th module of
brand/type "X" and it may not be stable. That doesn't
necessarily mean the "new" module is bad, removing any single
module might resolve the problem but you needed ALL of them.
Toward this end, purchase all the memory at once from someplace
that guarantees compatibility, like crucial.com.

 

[Daniel James]

In what way doesn't the KT800 support DDR RAM?

Brainfart. Sorry.

KT800 does support DDR and indeed dual-channel with a suitable
CPU/socket (see http://www.via.com.tw/en/k8-series/k8t800.jsp).

I think I must have got myself confused by the dual isses of
dual-channel and DDR RAM; and thought I had identified a reason to
prefer the nForce chipset (which, it seems I hadn't).

Also I've forgotten how Intel get away with doubling their quoted FSB
speeds compared to AMDs. What's the reason for that again?

Seems to me that intels FSB speeds are reasonable claims. I've never
really understood *what* it was that AMD claimed -- partly because I
don't fully understand their "hyperchannel" technology and how it
relates to FSB (or anything else). It seems reasonable to describe
dual-channel DDR memory at 200MHz as 800MHz (whether it's on a P4 or a
socket 939 A64) and also reasonable to suppose that 200MHz
single-channel DDR memory (as on a socket 754 A64) will be slower, No?

Cheers,
Daniel.

 

[Tony Houghton]

In <[email protected]>,

Brainfart. Sorry.

KT800 does support DDR and indeed dual-channel with a suitable
CPU/socket (see http://www.via.com.tw/en/k8-series/k8t800.jsp).

IOW it supports Socket 754, 939 and/or 940, with dual channel support on
the latter 2?

I think I must have got myself confused by the dual isses of
dual-channel and DDR RAM; and thought I had identified a reason to
prefer the nForce chipset (which, it seems I hadn't).

Preferring nForce is understandable, but personally I've never had a
problem with VIA, even running Speedtouch USB ADSL modems off at least 3
different VIA boards. Personally I think I'd prefer the VIA even if the
latest nForce is faster because of better Linux support.

Seems to me that intels FSB speeds are reasonable claims. I've never
really understood *what* it was that AMD claimed -- partly because I
don't fully understand their "hyperchannel" technology and how it
relates to FSB (or anything else). It seems reasonable to describe
dual-channel DDR memory at 200MHz as 800MHz (whether it's on a P4 or a
socket 939 A64) and also reasonable to suppose that 200MHz
single-channel DDR memory (as on a socket 754 A64) will be slower, No?

Of course, I forgot about dual channel. But for 32-bit at least, AMD
seem to stick to quoting the single-channel speeds even where dual
channel is supported.

 

[Daniel James]

IOW it supports Socket 754, 939 and/or 940, with dual channel
support on the latter 2?

That's my understanding. If anyone knows better I'm happy to be
corrected.

Preferring nForce is understandable, but personally I've never
had a problem with VIA, even running Speedtouch USB ADSL modems
off at least 3 different VIA boards. Personally I think I'd prefer
the VIA even if the latest nForce is faster because of better
Linux support.

Is it? I can't see anything on paper to suggest that the nForce is
better (or worse) now that you've set me straight on my DDR cock-up. I
know a few people round here are vehemently anti-VIA (their reasons
seeming to be that some now-obsolete VIA chipsets weren't up to much)
but the available facts don't seem to weight particularly in favour of
either, do they?

I have no experience of nForce chipsets and little of VIA (one EPIA
M10000 mobo - which has a VIA CPU so the VIA chipset is hardly
surprising - and that works fine), but I'm collecting intelligence for
the day when I build an AMD64 box.

linux support is an important factor. I hadn't even started to look at
that side, yet, though.

... for 32-bit at least, AMD seem to stick to quoting the
single-channel speeds even where dual channel is supported.

As I said, I have *real* difficulty making out just what the hell AMD
are describing half the time. I'm sure it'll become clearer as I learn
to read between the lines!

Cheers,
Daniel.

 

[Tony Houghton]

In <[email protected]>,

Is it? I can't see anything on paper to suggest that the nForce is
better (or worse) now that you've set me straight on my DDR cock-up. I
know a few people round here are vehemently anti-VIA (their reasons
seeming to be that some now-obsolete VIA chipsets weren't up to much)
but the available facts don't seem to weight particularly in favour of
either, do they?

The VIA drivers for Linux have been around for some time and mostly just
need a little tweaking when a new chipset comes out. The nForce drivers
are much newer and there were stability problems reported with nForce 2,
but maybe that's all fixed now.

I'm not sure whether all the features of either board are supported with
free drivers. NVidia are better at providing closed drivers, but closed
drivers of any sort, especially if your data integrity's relying on
them, are preferably avoided. I do see that the kernel now has VIA SATA
support, but I don't see any for nForce.

Do the latest nForce boards have SATA integrated into the Southbridge,
or do VIA still have the lead there? That's another potential issue.