Should I match RAM speed to FSB, or go for max speed?

[Gammit]

I have a Barton-core Athlon XP proc with 333 MHz FSB. I'm looking to get some new RAM, but can't decide between getting 333 MHz or 400 MHz RAM. Some people have told me to match the RAM frequencies to my FSB for better performance, while others told me to go for the faster speed. What are your opinions, and (if possible) could you point out any data to back it up?

[minibubba]

if you plan to OC your CPU then get the PC3200, if not then get the PC2700.

With the PC3200 you can easily push the FSB of your 2800+ to 200 mhz without stressing the RAM in the slightest and you can still have low timings

:cheers:

[Gammit]

I probably won't be overclocking. Thanks so far... any other input?

[Darthtanion]

Overclocking or not, I generally try to go for faster memory. Even if you have no intentions of pushing the system to its limits, the higher speed capacity will allow you to run more aggressive memory timings weith a greater degree of stability.

Oh, and FYI, the matching memory to bandwidth is bunk. The speeds are only a measure of the highest possible speeds that the module is guaranteed to run at with stability. It in no way is indicative of the speed that it must run at to be used.

[TheOne�]

i just put up a barton xp 2500+ in this comp but i took out a pc-2700 stick cause i felt like overclocking. if i upped the bus it just wouldn't start as the memory didn't support more. am gonna get another pc-3200 stick and 1 of those asus a7n8x deluxe boards and try 2 pump this 2 3000+ speeds. or more.

[kane2g]

As much as Darthtanion is right, hes also wrong.
PC2700 memory will run faster - yes, but thats overclocking.
Same with CPUs. XP1700 athlons are made to run 1.47Ghz. They can go faster, but that OCing.
So if youre not oveclocking your 333FSB Barton, get pc2700

[Darthtanion]

Hmmm... I fail to see where running more aggressive memory TIMINGS is consdered overclocking. Please school me in this matter. :confused:

As I stated, the more aggressive memory timings are generally a good deal more stable when using memory modules rated at a higher speed. This is certainly not overclocking as it does absolutely nothing to the FSB speeds of either the Northbridge to CPU speeds nor the speeds of the AGP/PCI bus channels. The better memory timings simply allow the memory and motherboard to work at a higher level of performance... and again, without changing any of the speeds of the system. I'm afraid that I will have to disagree with your thoughts.

[Gammit]

Thanks for all the great replies! After consideration (and finding a coupon), I ended up buying 2 512 MB 400 MHz dimms from Kingston for a great price. :thumb:

[Thoric]

for some reason my Kingmax ram doesnt like being @ 400mhz...(its 3200 400mhz rated)....

anyone with a little more experince in this than me could help?

a7n8x rev 2
xp 2500+
2x kingmax pc-3200 in dc

do i have to up the voltage a bit?

[Mista K6]

That'd help, also, can we have more info on your system specs?Also, what about your multi settings, RAM timings, sync. setting, etc. My best guess would be either to up the voltage a bit or relax the timings a bit (or both) and then o/c the FSB to 400 (200 x2) running the RAM in 1:1 sync with the FSB. THen you can either keep your multiplier at 9 to keep the CPU at stock speed (no clue why, unless your cooling isnt that great) or set the multiplier to 10, 10.5, or 11, to get a nice o/c (2-2.2GHz). However, that's just a standard o/c, the specs on your comp would help out alot :thumb: . : peace2: Mista K6

[Chezman29]

Yes, upping the Voltage will most likely be necessary for 2 reasons. One to get em' up to 200mhz, and for stability once you are there.
Try running them at 2.7v.

And all the info K6 asked, if you have any trouble.

Chez

[Gammit]

THen you can either keep your multiplier at 9 to keep the CPU at stock speed (no clue why, unless your cooling isnt that great) or set the multiplier to 10, 10.5, or 11, to get a nice o/c (2-2.2GHz).

Question: I have the XP 2800+ Barton Core. I'm considering overclocking by changing the multiplier. Do I have to physically unlock my chip first, or can I just adjust the multiplier in my BIOS settings?

Asus A7N8X Deluxe rev 2

[minibubba]

with that CPU and mobo you should be able to do it in the BIOS

[Thoric]

ok, here is what i got from my bios...

CPU External Frequency: 166MHz
System Perfomance: Optimal
CPU Interface: Optimal
Resulting Frequency: Optimal
Memory Timings: Optimal

SDRAM Active Precharge Delay: 7
SDRAM RAS to CAS Delay: 3
SDRAM RAS Precharge Delay: 3
SDRAM CAS Latency: 2.5T

FSB Spread Spectrum: Disabled
FSB Spread Spectrum: Disabled
CPU Vcore: 1.650V
Graphics Aperture Size: 128mb
AGP Frequency: Auto
DDR Reference Voltage: 2.6V
AGP VDDQ Voltage: 1.5v

i have a stock cooler on my Barton 2500+ voltage, so im not looking to overclock my CPU. it runs at about 42 doing not much so i dont want to push it till i get a new cooler...

Mista K6, are you saying put my Barton (333FSB) up to 400fsb? or just the memory...

[Mista K6]

Actually, EVERYTHING goes up to 400FSB. Ok, I dont know how much you know o/c'ing, but this is just a little background info. AMD systems run on a 2x bus (to run insync with DDR RAM), as opposed to the quadpumped (4x) bus of Intel systems. For instance, The stock 333 Bus is that 166MHz External frequency x 2. DDR 333 (PC2700) RAM also runs stock at this (166x2, hence DDR). However, DDR400 (PC3200) runs STOCK at 400 (200x2). Look in your BIOS for something called RAM sync ratio (it can be called by different names). Usually it'll be 1:1 or 4:3 or something. See, 1:1 means the RAM runs the same as the FSB and the CPU, i.e. a 333FSB with a CPU running at 333FSB and the RAM running at 333 (stock PC2700 RAM) (actually everything is running at 166x2, but anyways). 4:3 would mean the RAM is running at 4/3 the speed of the FSB (and CPU). A hypothetical system using this would be your 333FSB 2500+ running at 333, but having PC3200 runnings at 400. However, best performance is usually gotten from running everything in 1:1 ratio. So, using you CPU and PC3200 RAM, everything starts out at 333FSB (stock). Of course, running PC3200 at 333 is way under stock, hence we'll boost it up :thumb:. So, bit by bit you raise the MHz of the FSB (taking the RAM and CPU along with it) from 333 (you'll actually be raising the 166 number, but remember, its 166 x 2) to 400FSB. As you raise the MHz, raise the voltages a little, and check your temps to make sure your CPU cooler can handle it. Also, lower the multiplier as you go up, as running too high a multi can crash your comp too. You shouldnt have to relax the RAM timings because, even at 400, the PC3200 RAM is running at STOCK. The end product, providing everything goes well, should be a 400 FSB (your CPU running at 400 FSB ) and the RAM also running at 400. However, dont keep your stock multiplier of 11, cause 400 FSB at an 11 multiplier (200 x 11) is 2.2 GHz. Although the Barton can probably take it, you might not wanan try it yet. Relax the multi to 10 or 9 and see how your CPU runs. If its still cool enough, and everything is okey dokey, then you can increase it and get even more performance (maybe back up to 11). However, most of the performance gain will come from upping the FSB, as it runs your entire computer much faster now. Sry, that was really long, but I hoped it helped, reply back if you need more info or if I messed up up somewheres. : peace2: Mista K6