I copied that table CSV from GIT and filtered it to generate plots of frequency versus "CORE_CEFF" for a couple of different "VRATIO" values.
This link declares: https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.54.905&rep=rep1&type=pdf
Power ~= VDD2 x Fclk x Ceff
where the effective switched capacitance, Ceff, is commonly expressed as the product of the physical capacitance CL, and the activity weighting factor α, each averaged over the N nodes.
That link doesn't seem to work, do you happen to still know how to navigate to it or know the name of the paper. I tried looking on doi.org using the number in the link, but I don't think that's a complete DOI number.
Trying to follow along and I'm not certain what most of the abbreviations mean, so the column titles are a bit nonsense. Fratio ... Frequency ratio? But ratio of what to what? And
But I did reproduce the graph in python, which should make it a bit easier to iteratively view a bunch of plots:
import pandas as pd
import matplotlib.pyplot as plt
wof = pd.read_csv('WOF_V7_4_2_SFORZA_16_160_2500_TM.csv')
print("Unique Vratio indexes are: ", wof['VRATIO_INDEX'].unique())
# filter the table down to a plotable slice
def plotme(wf, vratio_index, nest_ceff=0.25, active_quads=6, fratio=1, plotit=True):
vratio = wf['VRATIO_START'][0] + vratio_index * wf['VRATIO_STEP'][0]
wf=wf[
(wf['FRATIO'] == fratio) &
(wf['ACTIVE_QUADS']==active_quads) &
(wf['NEST_CEFF']==nest_ceff) &
(wf['VRATIO_INDEX']==vratio_index) &
(wf['VRATIO']==vratio)
]
wf[['WOF_FREQ','CORE_CEFF']].plot(x='CORE_CEFF',
title=f'Fratio={fratio}, Vratio={vratio}, ACTIVE_QUADS={active_quads}, NEST_CEFF={nest_ceff}')
# plt.show() blocks the thread. If you don't call it, you can render several plots in the background and plt.show() them at once all later
if plotit:
plt.show()
plotme(wof, 12)
this works well pasted into an ipython prompt. I see most values for Vratio_index just plot a flat line, 12 and a couple of values near 12 make a nice graph. But why 12? And somewhat surprisingly changing the number of active quads doesn't seem to have any effect. Also what defines a quad as active? Simply that it's not powergated and completely off or does "active" mean high load?
And I think the number 1 question is "how does one know which CSV gets selected for a given CPU"?
EditPlotting all Vratio values as a 3d surface plot is interesting:
import pandas as pd
import matplotlib.pyplot as plt
from matplotlib import cm
from mpl_toolkits.mplot3d import Axes3D
def plotsurf(wf, file="", nest_ceff=0.25, active_quads=6, fratio=1, showplot=True, use_index=False):
# the VRATIO_START column is always the same value, as far as I've noticed
wf=wf[
(wf['FRATIO'] == fratio) &
(wf['ACTIVE_QUADS']==active_quads) &
(wf['NEST_CEFF']==nest_ceff)
]
vratio = wf['VRATIO_INDEX'] if use_index else wf['VRATIO']
ax = plt.figure().add_subplot(projection='3d')
ax.plot_trisurf(wf['CORE_CEFF'], vratio, wf['WOF_FREQ'], cmap=cm.jet, linewidth=0.2)
ax.set_title(f'{file}\nFratio={fratio}, ACTIVE_QUADS={active_quads}, NEST_CEFF={nest_ceff}')
ax.set_xlabel('Core_Ceff')
ax.set_ylabel('Vratio')
ax.set_zlabel('WOF_Hz')
ax.view_init(15, 60, 0)
if showplot:
plt.show()
return ax
(
EDIT: graphs should show vratio from 0-1. I fixed a bug in the above code which caused the values greater than 1 shown, but I didn't take new screenshots...
and I see from
the file in hostboot where the error is generated that
4.98699| UserData1 Number of cores : 0x00100002000000a0
4.98700| UserData2 WOF Power Mode (1=Nominal, 2=Turbo) : 0x000009c400000012
means 12core, "mode=2" (turbo?) 160w, 2500MHz, with header().size=12. Looking at the
SFORZA list, that's a 1800-2500MHz part with 3.8GHz turbo. Intuitively it' makes sense that table matches that CPU. But, also looking at the SFORZA list, every CPU on the list supports turbo mode to at least 3.8GHz, sometimes 4.1GHz.
So why are so many of the tables suffixed with
_NM.csv? There's a
WOF_V7_4_2_SFORZA_16_140_2200_NM.csv, but I don't see
any 140w 16core SFORZAs on the list. And plotting it the same as the other, it still goes to 3.8GHz despite the "2200MHz normal mode" file label.
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