What is Performance Level?

[method526]

could someone tell me the significance of performance level? should i set it higher or lower and why? relation to the NB? i'm kinda new to the more complex motherboards so i want to know this before i test with the RAM and such. thanks.

[fatguy1992]

Low performance is better. But as you increase the FSB u'll have to raise it

From my testing

400FSB = PL 7
450FSB = PL 8
500FSB = PL 9

Some mobos can run lower PL then others.

[RPGWiZaRD]

It's one of the settings that have a major impact on memory performance.

Depends on RAM and chipset type and FSB and RAM frequency and NB volts, what PL you can run. If we compare Intel P35 vs P45 chipset for example it seems P35 allows for 1 - 2 steps lower PL in general. I personally run PL7 at 500 FSB with CellShock Micron D9GKX RAM on my Gigabyte P35 DS4 board with a minor increase in NB voltage at the 1:1 divider, if I use 1.2x divider so I get DDR2-1200 I'll have to use PL8 or increase NB voltage to perhaps somewhat unsafe levels.

PL7 at 500 fsb and DDR2-1000 4-4-4-8 timings provide me neat RAM performance though:



EDIT, added PL8:



and PL9 performance comparision:



As you see it quickly affects read b/w and latency.

[Thrmionicshaman]

Low performance is better. But as you increase the FSB u'll have to raise it

From my testing

400FSB = PL 7
450FSB = PL 8
500FSB = PL 9

Some mobos can run lower PL then others.

Indeed.
It seems with my DFI p35 T2R I can do PL5 up to about 422 FSB with 1.37- 1.41V and PL8 with all the phases pulled in to 7 with 1.5V for 500 FSB. Gigabyte and especially P45 NB do not usually afford such a luxury, At least, that is what I have read, but P45 can clock FSB higher at the expense of higher PL.
Divide the PL by the FSB to get your acess time in nanoseconds. Same thing for CAS/Actual Mem MHz-not DDR MHz.
@Method and anyone really-Here is a cool link explaining some of the technical stuff about PL, there are some cool equations too
Hope you enjoy
"Why we were wrong about the Intel X48"
http://www.anandtech.com/mb/showdoc.aspx?i=3208&p=1
and more- http://www.tweakers.fr/timings.html
and moreagain-http://www.thetechrepository.com/showthread.php?t=160
http://www.thetechrepository.com/showthread.php?t=195

@RPGWizard nice bandwidth BTW!

[RPGWiZaRD]

@RPGWizard nice bandwidth BTW!

Yea it's a pretty performance efficient setting concidering I run the old E8400 CPU at 4.0GHz only (but 500 FSB).

These RAM sticks are like representing the very best DDR2 out there though and I feel bad of running them at only DDR2-1000 4-4-4-8, granted at a VERY tight timings config at PL7 and TRFC 25 etc. But my old E8400 C0 stepping dies after 4.0GHz+ and starts eating voltage for breakfast, I may try to see if 512x8 is possible with some further tweaking when I get bored and performance with 9x CPU multi sux, would need approx ~4.2GHz+ for it to be worth using!

I can also run the RAM sticks just fine at DDR2-1200 5-5-4-10 PL8.



But as you can see it's not really worth it, I get some extra b/w but also latency is higher and I prefer it to be sub 50 and I prefer the 48.8~49 ms I get at DDR2-1000 4-4-4-8 PL7 at only slightly lower b/w.

Oh and did I mention the RAM sticks runs at only ~2.15v, I haven't tried going lower as they are rated for 2.1 - 2.3v and I use 2x80mm fans over them (It was a habit I started with my old UTT DDR1 OCZ Gold VX sticks @ 3.2~3.3v :P), so I'm fine with 2.15v even if say 2.1v was enough. ^^ NB voltage is set to +0.15v in BIOS.

Don't have any memtest screen of DDR2-1200 5-5-4-10 saved but for DDR2-1000 4-4-4-8 I found this:



I'm a fan of performance efficient configs and therefore I haven't upgraded from P35 chipset knowing I can't probably get similiar RAM performance as with this P35 DS4 board config. I'd have to try push the voltage higher before I upgrade next time but I smell DDR2-1200 CL4 possible at around 2.25~2.3v.

[Xello]

The Origins of Static Read Control Delay (tRD)

[method526]

here's my results on PL7 running 1200 on an ASUS Rampage Formula X48. nb has 1.39v and ram is running 2.1v
think this is OK or should i change some things? my Q6600 is running 450 x 8 on 1.4v

[JohnZS]

All I know is that it is an option which is not in my BIOS
P5E3 (standard) manages that thing by itself, @ 400FSB I can only run my 1600Mhz RAM @ 1333Mhz CL6 with a automatic PL of 8, I try to force PL of 7, but the system becomes unstable... I guess this is because I have 8GB of RAM
all in all PL is a good feature for those that have it as you can boost memory performance
John

[zanzabar]

All I know is that it is an option which is not in my BIOS
P5E3 (standard) manages that thing by itself, @ 400FSB I can only run my 1600Mhz RAM @ 1333Mhz CL6 with a automatic PL of 8, I try to force PL of 7, but the system becomes unstable... I guess this is because I have 8GB of RAM
all in all PL is a good feature for those that have it as you can boost memory performance
John

are u sure that your board dosnt have it asus calls it something retarded and makes a +- based on an arbitrary number, its like ai booser or something

[JohnZS]

Yeah, it's called Transaction Booster, but sadly in the P5E3 BIOS, we do not have the "manual option" so we cannot set a common performance level, it's some strange guess work.
Transaction Booster = Enabled Level 2 usually gives you a performance level of 7, enable level 1 = PL8
Disable Level 1 = a slack 8, Disable Level 2 = PL9
I wish ASUS brought our BIOS in line with other P5E3 X38/X48 boards as they have a Common Performance Level option under Transaction Booster
John