Which CPU?

[Sibu]

My brother has decided he wants to upgrade his pc, specifically his CPU, and i'm not sure which to recommend to him.

Theres no point in the Barton's as thats a bit out of his price range, but a quick look on cpucity gives these prices:

XP1800 OEM Thoroughbred cores JUICB £38.78

or

AMD DURON 1.6GHZ OEM £31.72

or

AMD DURON 1.8GHZ OEM £39.95

These are about the price range he is looking at, and i was wondering which would be most suitable.

Obviously overclockability should be taken into account tho he only has 256MB DDR (borrowed from me) at the moment.

So which should i get for him?

And is it worth buying an Abit NF7-s for him, or would a cheaper mobo do for his needs?

[Howard]

What mobo and CPU has he got at present?

A cheaper mobo will suffice if he isn't a "power user" intent on overclocking and what-not.

[blockers]

Well give us a buget and we can give you some more info.

Based on that i would go for the xp1800 tbred. As it will overclock, and is more powerful (more cache than the durons.)

a) What buget?
b) What board does he have?
c) What RAM is it? (manu/speed)

Will

[Sibu]

Errr,

Budget is mobo may be being paid for as Xmas pressie...but the question is, is an expensive mobo worth it or not?

I'm buying the CPU, so about 40 quid for that

The board he has atm is a Gigabyte ga-7ixe4 which only takes nvram, ie sucky and old carp from 2 yrs ago.

The RAM im supplying him will be the old DDR ram, again bought 2yrs ago. Not sure what clock speeds it is. i think its 166mhz.

So oc isnt a huge priority, but even with crap ram you can oc the chip a bit right?

EDIT: spellings and wrong info

[TiG]

There is no question what chip to buy, it has to be the 1800xp, there is no decision to be made at all.

The power of the xp is much better than the 1800xp, it could if your mb is okay be clocked to a good 2gig, probably only at say 175fsb if your memory or motherboard isn't that great.

But i can't stress enough avoid the duron's

TiG

[Sibu]

Thats what i heard, apart from the various potentially good things of oc the duron 1.6 after unlocking the L2 cache

[TiG]

what L2 cache?

[Sibu]

2bh, im not really sure it was on another thread here.

Ignore that then. XP 1800+ hands down then

[Donny John]

Get the XP1800+

[Galant]

If you can order from the USA, newegg has The Abit NF7-S on sale for about $87. But you'll have to order in the next few days.

That's somewhere between 50 and 60 pounds sterling.

(Ducks for cover expecting incoming assistance requests! )

[Saracen]

Originally posted by TiG
what L2 cache?

Duron's have 128KB of L2 cache in addition to 64KB of L1 cache, giving a total of 192KB. This compares to 128KB of L1 and either 256KB or 512KB L2 on Athlon XP's, giving either 384KB or 640KB for Athlon XP's.

Don't get TOO hung up on cache size, though, and be aware that the SIZE is only one aspect of cache performance.

Put it in context. CPU's operate at speeds far faster than main memory, let alone hard drives, are capable of keeping up with, and if the CPU doesn't have have the next bit of data when it needs it, then it is going to sit there twiddling it's thumbs and tapping it's foot 'til the rest of the system catches up. So, cache is there to try to keep the CPU supplied with data as much of the time as possible.

L1 cache typcially runs at the same speed as the processor and is the fastest memory in the machine ...... but it's also the most expensive. As a compromise, many CPU's also have cheaper (but still much faster than main system memory) L2 cache as well.

However, what matters is not whether the memory is fast or slow, large or small, but rather whether the cache has the data when the CPU needs it or not ... and THAT is as much down to the algorithms that define how the cache works as it is the size and speed. It is also FAR harder to assess.

This is also one of the differences between Intel and AMD designs - AMD use exclusive cache, Intel use Inclusive. AMD would argue that the elimiation of data duplication between L1 and L2 using exclusive caches increases the effectiveness of their cache over Intel, regardless of absolute size.

At least as important as the speed and size of the cache is the algoritm that determines what data is kept (or fetched into) cache ready for the processor's anticipated demands. After all, there's no point in having a larger cache if the algorithm is so poor that it always dumps the wrong data just before the cache needs to supply it to the CPU. This is why AMD place emphasis on features like hardware data pre-fetch and their translation look-aside buffers. When they switched from the original Athlons to the XP technology, they included a number of design enhancements, especially to the cache technology (including the hardware data pre-fetch and exclusive and speculative TLB's) and THAT is why they switched to the XP's PR rating - because these technologies gave a significant boost to overall processor performance without increasing clock speed.

This stuff is largely what AMD's Quantispeed stuff is all about and why I said not to get to hung up on paper spec's, like cache size and speed. At the end of the day, who CARES what the size and speed are UNLESS they have a beneficial effect on performance. It is, after all, "work done" that matters, not megahertz, cache size of FSB.

[mike_w]

If anyone knows the benchmark scores difference between these processors (in things like 3DMark), can they post them please (i know that other things like graphics card can affect performance, but if you find two almost identical systems except for processor that that would be great!)

[malice19]

I would probably Get the XP1800+....

*******************
I’m broke as per usual but want 2 put a AMD ATHLON 1200 266FSB in my brothers pc ....
How much do you think I should pay for that chip nower days ?


saw a few on eBay....for £25

[Sibu]

1800+ it is then

[mobo]

xp1800+ then overclock it!, my xp1700+ has been running @2200 for the last 6 months no problems.