diff --git a/conda_splade_env.yml b/conda_splade_env.yml
index e1d9b0c..09280df 100644
--- a/conda_splade_env.yml
+++ b/conda_splade_env.yml
@@ -1,6 +1,7 @@
 name: splade
 channels:
   - pytorch
+  - conda-forge
   - defaults
 dependencies:
   - _libgcc_mutex=0.1=main
@@ -10,19 +11,26 @@ dependencies:
   - aiosignal=1.2.0=pyhd3eb1b0_0
   - async-timeout=4.0.1=pyhd3eb1b0_0
   - attrs=21.4.0=pyhd3eb1b0_0
+  - binutils=2.35.1=hdd6e379_2
+  - binutils_impl_linux-64=2.35.1=h27ae35d_9
+  - binutils_linux-64=2.35.1=h454624a_30
   - blas=1.0=mkl
   - blinker=1.4=py38h06a4308_0
   - brotli=1.0.9=he6710b0_2
   - brotlipy=0.7.0=py38h27cfd23_1003
   - bzip2=1.0.8=h7b6447c_0
   - c-ares=1.18.1=h7f8727e_0
-  - ca-certificates=2022.4.26=h06a4308_0
+  - c-compiler=1.2.0=h7f98852_0
+  - ca-certificates=2022.6.15=ha878542_0
   - cachetools=4.2.2=pyhd3eb1b0_0
-  - certifi=2021.10.8=py38h06a4308_2
+  - certifi=2022.6.15=py38h578d9bd_0
   - cffi=1.15.0=py38hd667e15_1
   - charset-normalizer=2.0.4=pyhd3eb1b0_0
+  - click=8.1.3=py38h578d9bd_0
+  - cmake=3.20.2=h541d2ed_0
   - cryptography=36.0.0=py38h9ce1e76_0
   - cudatoolkit=11.3.1=h2bc3f7f_2
+  - cxx-compiler=1.2.0=h4bd325d_0
   - cycler=0.11.0=pyhd3eb1b0_0
   - dataclasses=0.8=pyh6d0b6a4_7
   - dbus=1.13.18=hb2f20db_0
@@ -32,6 +40,8 @@ dependencies:
   - fonttools=4.25.0=pyhd3eb1b0_0
   - freetype=2.11.0=h70c0345_0
   - frozenlist=1.2.0=py38h7f8727e_0
+  - gcc_impl_linux-64=9.3.0=h70c0ae5_19
+  - gcc_linux-64=9.3.0=h1ee779e_30
   - giflib=5.2.1=h7b6447c_0
   - glib=2.69.1=h4ff587b_1
   - gmp=6.2.1=h2531618_2
@@ -41,6 +51,8 @@ dependencies:
   - grpcio=1.42.0=py38hce63b2e_0
   - gst-plugins-base=1.14.0=h8213a91_2
   - gstreamer=1.14.0=h28cd5cc_2
+  - gxx_impl_linux-64=9.3.0=hd87eabc_19
+  - gxx_linux-64=9.3.0=h7e70986_30
   - h5py=3.6.0=py38ha0f2276_0
   - hdf5=1.10.6=hb1b8bf9_0
   - icu=58.2=he6710b0_3
@@ -48,11 +60,17 @@ dependencies:
   - importlib-metadata=4.11.3=py38h06a4308_0
   - intel-openmp=2021.4.0=h06a4308_3561
   - jpeg=9e=h7f8727e_0
+  - kernel-headers_linux-64=2.6.32=he073ed8_15
   - kiwisolver=1.3.2=py38h295c915_0
+  - krb5=1.19.2=hcc1bbae_0
   - lame=3.100=h7b6447c_0
   - lcms2=2.12=h3be6417_0
   - ld_impl_linux-64=2.35.1=h7274673_9
+  - libcurl=7.82.0=h0b77cf5_0
+  - libedit=3.1.20210910=h7f8727e_0
+  - libev=4.33=h516909a_1
   - libffi=3.3=he6710b0_2
+  - libgcc-devel_linux-64=9.3.0=h7864c58_19
   - libgcc-ng=9.3.0=h5101ec6_17
   - libgfortran-ng=7.5.0=ha8ba4b0_17
   - libgfortran4=7.5.0=ha8ba4b0_17
@@ -60,8 +78,11 @@ dependencies:
   - libiconv=1.16=h7f8727e_2
   - libidn2=2.3.2=h7f8727e_0
   - libllvm11=11.1.0=h3826bc1_1
+  - libnghttp2=1.46.0=hce63b2e_0
   - libpng=1.6.37=hbc83047_0
   - libprotobuf=3.19.1=h4ff587b_0
+  - libssh2=1.10.0=h8f2d780_0
+  - libstdcxx-devel_linux-64=9.3.0=hb016644_19
   - libstdcxx-ng=9.3.0=hd4cf53a_17
   - libtasn1=4.16.0=h27cfd23_0
   - libtiff=4.2.0=h85742a9_0
@@ -90,7 +111,8 @@ dependencies:
   - numpy-base=1.21.5=py38hf524024_1
   - oauthlib=3.1.0=py_0
   - openh264=2.1.1=h4ff587b_0
-  - openssl=1.1.1n=h7f8727e_0
+  - openjdk=11.0.13=h87a67e3_0
+  - openssl=1.1.1o=h7f8727e_0
   - packaging=21.3=pyhd3eb1b0_0
   - pcre=8.45=h295c915_0
   - pillow=9.0.1=py38h22f2fdc_0
@@ -105,18 +127,20 @@ dependencies:
   - pysocks=1.7.1=py38h06a4308_0
   - python=3.8.13=h12debd9_0
   - python-dateutil=2.8.2=pyhd3eb1b0_0
+  - python_abi=3.8=2_cp38
   - pytorch=1.11.0=py3.8_cuda11.3_cudnn8.2.0_0
   - pytorch-mutex=1.0=cuda
   - qt=5.9.7=h5867ecd_1
   - readline=8.1.2=h7f8727e_1
   - requests=2.27.1=pyhd3eb1b0_0
   - requests-oauthlib=1.3.0=py_0
+  - rhash=1.4.1=h7f98852_0
   - rsa=4.7.2=pyhd3eb1b0_1
   - setuptools=61.2.0=py38h06a4308_0
   - sip=4.19.13=py38h295c915_0
   - six=1.16.0=pyhd3eb1b0_1
   - sqlite=3.38.2=hc218d9a_0
-  - tbb=2021.5.0=hd09550d_0
+  - sysroot_linux-64=2.12=he073ed8_15
   - tensorboard=2.6.0=py_1
   - tensorboard-data-server=0.6.0=py38hca6d32c_0
   - tensorboard-plugin-wit=1.6.0=py_0
@@ -126,38 +150,79 @@ dependencies:
   - tornado=6.1=py38h27cfd23_0
   - typing-extensions=4.1.1=hd3eb1b0_0
   - typing_extensions=4.1.1=pyh06a4308_0
-  - urllib3=1.26.9=py38h06a4308_0
   - werkzeug=2.0.3=pyhd3eb1b0_0
   - wheel=0.37.1=pyhd3eb1b0_0
   - xz=5.2.5=h7b6447c_0
   - yarl=1.6.3=py38h27cfd23_0
+  - zipp=3.8.0=py38h06a4308_0
   - zlib=1.2.12=h7f8727e_2
   - zstd=1.4.9=haebb681_0
   - pip:
     - antlr4-python3-runtime==4.8
+    - beautifulsoup4==4.11.1
     - beir==1.0.0
-    - click==8.1.3
+    - blis==0.7.8
+    - catalogue==2.0.7
+    - cssselect==1.1.0
+    - cymem==2.0.6
+    - cython==0.29.30
     - elasticsearch==7.9.1
     - faiss-cpu==1.7.2
+    - feedfinder2==0.0.4
+    - feedparser==6.0.10
     - filelock==3.6.0
+    - flatbuffers==2.0
     - huggingface-hub==0.5.1
     - hydra-core==1.1.2
     - importlib-resources==5.2.3
+    - jieba3k==0.35.1
+    - jinja2==3.1.2
     - joblib==1.1.0
+    - langcodes==3.3.0
+    - lightgbm==3.3.2
+    - lxml==4.6.3
+    - markupsafe==2.1.1
+    - murmurhash==1.0.7
+    - newspaper3k==0.2.8
     - nltk==3.7
+    - nmslib==2.1.1
     - omegaconf==2.1.2
+    - onnxruntime==1.11.1
+    - pandas==1.4.3
+    - pathy==0.6.2
+    - preshed==3.0.6
+    - psutil==5.9.1
+    - pybind11==2.6.1
+    - pydantic==1.8.2
+    - pyjnius==1.4.2
     - pyparsing==3.0.8
+    - pyserini==0.17.0
     - pytrec-eval==0.5
     - pyyaml==6.0
     - regex==2022.4.24
+    - requests-file==1.5.1
     - sacremoses==0.0.53
     - scikit-learn==1.0.2
     - scipy==1.8.0
     - sentence-transformers==2.2.0
     - sentencepiece==0.1.96
+    - sgmllib3k==1.0.0
+    - smart-open==5.2.1
+    - soupsieve==2.3.2.post1
+    - spacy==3.3.1
+    - spacy-legacy==3.0.9
+    - spacy-loggers==1.0.2
+    - srsly==2.4.3
+    - tbb==2021.6.0
+    - tbb-devel==2021.6.0
+    - thinc==8.0.17
     - threadpoolctl==3.1.0
+    - tinysegmenter==0.3
+    - tldextract==3.3.0
     - tokenizers==0.12.1
     - tqdm==4.64.0
     - transformers==4.18.0
-    - zipp==3.8.0
-prefix: /home/classanc/miniconda3/envs/splade
+    - typer==0.4.2
+    - urllib3==1.25.11
+    - warcio==1.7.4
+    - wasabi==0.9.1
\ No newline at end of file
diff --git a/conf/efficient_splade/config_BT_VI_large.yaml b/conf/efficient_splade/config_BT_VI_large.yaml
new file mode 100644
index 0000000..84af1d2
--- /dev/null
+++ b/conf/efficient_splade/config_BT_VI_large.yaml
@@ -0,0 +1,32 @@
+# @package _global_
+
+# FILES
+defaults: # (these specify which config FILES to use)
+  ############## TRAIN ###################################
+  - ../train/config: efficient_splade
+  - ../train/data: distil_from_ensemble
+  - ../train/model: separate_mixed_mlmflops
+  ############## INDEX ###################################
+  - ../index: msmarco
+  ############## RETRIEVE ################################
+  - ../retrieve_evaluate: all
+  ############### FLOPS ##################################
+  - ../flops: msmarco
+
+# Direct PARAMETER setting
+config:
+  loss: KlDiv
+  regularizer:
+    FLOPS:
+      lambda_d: 5e-4
+      T: 50000
+      targeted_rep: rep
+      reg: FLOPS
+    L1:
+      lambda_q: 5e-4
+      T: 50000
+      targeted_rep: rep
+      reg: L1
+  checkpoint_dir: models/efficient/VI/BT/large/checkpoint
+  index_dir: models/efficient/VI/BT/large/index
+  out_dir: models/efficient/VI/BT/large/out
\ No newline at end of file
diff --git a/conf/efficient_splade/config_BT_VI_medium.yaml b/conf/efficient_splade/config_BT_VI_medium.yaml
new file mode 100644
index 0000000..6758ead
--- /dev/null
+++ b/conf/efficient_splade/config_BT_VI_medium.yaml
@@ -0,0 +1,32 @@
+# @package _global_
+
+# FILES
+defaults: # (these specify which config FILES to use)
+  ############## TRAIN ###################################
+  - ../train/config: efficient_splade
+  - ../train/data: distil_from_ensemble
+  - ../train/model: separate_mixed_mlmflops
+  ############## INDEX ###################################
+  - ../index: msmarco
+  ############## RETRIEVE ################################
+  - ../retrieve_evaluate: all
+  ############### FLOPS ##################################
+  - ../flops: msmarco
+
+# Direct PARAMETER setting
+config:
+  loss: KlDiv
+  regularizer:
+    FLOPS:
+      lambda_d: 5e-4
+      T: 50000
+      targeted_rep: rep
+      reg: FLOPS
+    L1:
+      lambda_q: 5e-3
+      T: 50000
+      targeted_rep: rep
+      reg: L1
+  checkpoint_dir: models/efficient/VI/BT/medium/checkpoint
+  index_dir: models/efficient/VI/BT/medium/index
+  out_dir: models/efficient/VI/BT/medium/out
\ No newline at end of file
diff --git a/conf/efficient_splade/config_BT_VI_small.yaml b/conf/efficient_splade/config_BT_VI_small.yaml
new file mode 100644
index 0000000..74514fe
--- /dev/null
+++ b/conf/efficient_splade/config_BT_VI_small.yaml
@@ -0,0 +1,32 @@
+# @package _global_
+
+# FILES
+defaults: # (these specify which config FILES to use)
+  ############## TRAIN ###################################
+  - ../train/config: efficient_splade
+  - ../train/data: distil_from_ensemble
+  - ../train/model: separate_mixed_mlmflops
+  ############## INDEX ###################################
+  - ../index: msmarco
+  ############## RETRIEVE ################################
+  - ../retrieve_evaluate: all
+  ############### FLOPS ##################################
+  - ../flops: msmarco
+
+# Direct PARAMETER setting
+config:
+  loss: KlDiv
+  regularizer:
+    FLOPS:
+      lambda_d: 5e-3
+      T: 50000
+      targeted_rep: rep
+      reg: FLOPS
+    L1:
+      lambda_q: 5e-3
+      T: 50000
+      targeted_rep: rep
+      reg: L1
+  checkpoint_dir: models/efficient/VI/BT/small/checkpoint
+  index_dir: models/efficient/VI/BT/small/index
+  out_dir: models/efficient/VI/BT/small/out
\ No newline at end of file
diff --git a/conf/efficient_splade/config_V_from_huggingface.yaml b/conf/efficient_splade/config_V_from_huggingface.yaml
new file mode 100644
index 0000000..6620e83
--- /dev/null
+++ b/conf/efficient_splade/config_V_from_huggingface.yaml
@@ -0,0 +1,26 @@
+# @package _global_
+
+# FILES
+defaults: # (these specify which config FILES to use)
+  ############## INDEX ###################################
+  - ../index: msmarco
+  ############## RETRIEVE ################################
+  - ../retrieve_evaluate: all
+  ############### FLOPS ##################################
+  - ../flops: msmarco
+
+# Direct PARAMETER setting
+config:
+  checkpoint_dir: models/hf/V/large/checkpoint
+  index_dir:  models/hf/V/large/index
+  out_dir:  models/hf/V/large/out
+  pretrained_no_yamlconfig: true
+  tokenizer_type: naver/efficient-splade-V-large-doc
+  index_batch_size: 500
+  eval_batch_size: 500
+init_dict:
+  model_type_or_dir: naver/efficient-splade-V-large-doc
+  model_type_or_dir_q: naver/efficient-splade-V-large-query
+  freeze_d_model: 0
+  agg: max
+  fp16: true
\ No newline at end of file
diff --git a/conf/efficient_splade/config_V_large.yaml b/conf/efficient_splade/config_V_large.yaml
new file mode 100644
index 0000000..3115d4f
--- /dev/null
+++ b/conf/efficient_splade/config_V_large.yaml
@@ -0,0 +1,32 @@
+# @package _global_
+
+# FILES
+defaults: # (these specify which config FILES to use)
+  ############## TRAIN ###################################
+  - ../train/config: efficient_splade
+  - ../train/data: distil_from_ensemble
+  - ../train/model: separate_distilbert_mlmflops
+  ############## INDEX ###################################
+  - ../index: msmarco
+  ############## RETRIEVE ################################
+  - ../retrieve_evaluate: all
+  ############### FLOPS ##################################
+  - ../flops: msmarco
+
+# Direct PARAMETER setting
+config:
+  loss: KlDiv
+  regularizer:
+    FLOPS:
+      lambda_d: 5e-4
+      T: 50000
+      targeted_rep: rep
+      reg: FLOPS
+    L1:
+      lambda_q: 5e-4
+      T: 50000
+      targeted_rep: rep
+      reg: L1
+  checkpoint_dir: models/efficient/V/large/checkpoint
+  index_dir: models/efficient/V/large/index
+  out_dir: models/efficient/V/large/out
\ No newline at end of file
diff --git a/conf/efficient_splade/config_V_medium.yaml b/conf/efficient_splade/config_V_medium.yaml
new file mode 100644
index 0000000..8948eed
--- /dev/null
+++ b/conf/efficient_splade/config_V_medium.yaml
@@ -0,0 +1,32 @@
+# @package _global_
+
+# FILES
+defaults: # (these specify which config FILES to use)
+  ############## TRAIN ###################################
+  - ../train/config: efficient_splade
+  - ../train/data: distil_from_ensemble
+  - ../train/model: separate_distilbert_mlmflops
+  ############## INDEX ###################################
+  - ../index: msmarco
+  ############## RETRIEVE ################################
+  - ../retrieve_evaluate: all
+  ############### FLOPS ##################################
+  - ../flops: msmarco
+
+# Direct PARAMETER setting
+config:
+  loss: KlDiv
+  regularizer:
+    FLOPS:
+      lambda_d: 5e-4
+      T: 50000
+      targeted_rep: rep
+      reg: FLOPS
+    L1:
+      lambda_q: 5e-3
+      T: 50000
+      targeted_rep: rep
+      reg: L1
+  checkpoint_dir: models/efficient/V/medium/checkpoint
+  index_dir: models/efficient/V/medium/index
+  out_dir: models/efficient/V/medium/out
\ No newline at end of file
diff --git a/conf/efficient_splade/config_V_small.yaml b/conf/efficient_splade/config_V_small.yaml
new file mode 100644
index 0000000..c027804
--- /dev/null
+++ b/conf/efficient_splade/config_V_small.yaml
@@ -0,0 +1,32 @@
+# @package _global_
+
+# FILES
+defaults: # (these specify which config FILES to use)
+  ############## TRAIN ###################################
+  - ../train/config: efficient_splade
+  - ../train/data: distil_from_ensemble
+  - ../train/model: separate_distilbert_mlmflops
+  ############## INDEX ###################################
+  - ../index: msmarco
+  ############## RETRIEVE ################################
+  - ../retrieve_evaluate: all
+  ############### FLOPS ##################################
+  - ../flops: msmarco
+
+# Direct PARAMETER setting
+config:
+  loss: KlDiv
+  regularizer:
+    FLOPS:
+      lambda_d: 5e-3
+      T: 50000
+      targeted_rep: rep
+      reg: FLOPS
+    L1:
+      lambda_q: 5e-3
+      T: 50000
+      targeted_rep: rep
+      reg: L1
+  checkpoint_dir: models/efficient/V/small/checkpoint
+  index_dir: models/efficient/V/small/index
+  out_dir: models/efficient/V/small/out
diff --git a/conf/train/config/efficient_splade.yaml b/conf/train/config/efficient_splade.yaml
new file mode 100644
index 0000000..c179d69
--- /dev/null
+++ b/conf/train/config/efficient_splade.yaml
@@ -0,0 +1,20 @@
+# @package config
+
+lr: 2e-5
+seed: 123
+gradient_accumulation_steps: 1
+weight_decay: 0.01
+validation_metrics: [ MRR@10, recall@100, recall@200, recall@500 ]
+pretrained_no_yamlconfig: false
+nb_iterations: 250000
+train_batch_size: 128  # number of gpus needs to divide this
+eval_batch_size: 600
+index_retrieve_batch_size: 500
+record_frequency: 10000
+train_monitoring_freq: 500
+warmup_steps: 6000
+max_length: 256
+fp16: true
+matching_type: splade
+monitoring_ckpt: MRR@10  # or e.g. MRR@10
+overwrite_final: true
\ No newline at end of file
diff --git a/conf/train/model/separate_distilbert_mlmflops.yaml b/conf/train/model/separate_distilbert_mlmflops.yaml
new file mode 100644
index 0000000..0696e02
--- /dev/null
+++ b/conf/train/model/separate_distilbert_mlmflops.yaml
@@ -0,0 +1,11 @@
+# @package _global_
+
+init_dict:
+  model_type_or_dir: models/mlm_flops/DistilBERT
+  model_type_or_dir_q: models/mlm_flops/DistilBERT
+  freeze_d_model: 0
+  agg: max
+  fp16: true
+
+config:
+  tokenizer_type: models/mlm_flops/DistilBERT
\ No newline at end of file
diff --git a/conf/train/model/separate_mixed_mlmflops.yaml b/conf/train/model/separate_mixed_mlmflops.yaml
new file mode 100644
index 0000000..bd37526
--- /dev/null
+++ b/conf/train/model/separate_mixed_mlmflops.yaml
@@ -0,0 +1,11 @@
+# @package _global_
+
+init_dict:
+  model_type_or_dir: models/mlm_flops/DistilBERT
+  model_type_or_dir_q: models/mlm_flops/BERTiny
+  freeze_d_model: 0
+  agg: max
+  fp16: true
+
+config:
+  tokenizer_type: models/mlm_flops/DistilBERT
\ No newline at end of file
diff --git a/efficient_splade_pisa/README.md b/efficient_splade_pisa/README.md
new file mode 100644
index 0000000..f8de7ed
--- /dev/null
+++ b/efficient_splade_pisa/README.md
@@ -0,0 +1,64 @@
+## Step 0 - Install pisa from the weight-queries branch
+
+The pre-requisite step is to install pisa. Note that it could take a while. 
+
+```
+git clone https://github.com/pisa-engine/pisa.git
+cd pisa
+git checkout weight-queries
+mkdir build
+cd build
+cmake .. -DCMAKE_BUILD_TYPE=Release
+make
+cd ../../ 
+```
+
+## Step 1 - Download indexes and queries and extract here
+
+```
+wget https://www.dropbox.com/s/odkkbgg8lopcduk/pisa_index.tar.gz?dl=0 -O pisa_index.tar.gz
+tar xzvf pisa_index.tar.gz
+```
+
+## Step 2 - Run parallel retrieval to get QPS and effectiveness
+
+```
+export level=level_5 #level_5 for V) and level_6 for VI)
+export size=large # small, medium or large
+
+pisa/build/bin/evaluate_queries \
+                                   --encoding block_simdbp \
+                                   --documents indexes/$level/$size.docmap \
+                                   --index indexes/$level/$size.block_simdbp.idx \
+                                   --wand indexes/$level/$size.fixed-40.bmw \
+                                   --algorithm block_max_wand \
+                                   -k 1000 \
+                                   --scorer quantized \
+                                   --weighted \
+                                   --queries queries/$level/$size.pisa.ints \
+                                   --run "$level/$size" > ${level}_${size}.trec
+
+python -m pyserini.eval.trec_eval -c -M 10 -m recip_rank msmarco-passage-dev-subset ${level}_${size}.trec
+python -m pyserini.eval.trec_eval -c -mrecall msmarco-passage-dev-subset ${level}_${size}.trec
+
+```
+
+## Step 3 - Run mono-batch mono-cpu retrieval to get average latency
+
+
+```
+level=level_6 #level_5 for V) and level_6 for VI)
+size=medium # small, medium or large
+
+pisa/build/bin/queries \
+                            --encoding block_simdbp \
+                            --index indexes/$level/$size.block_simdbp.idx \
+                            --wand indexes/$level/$size.fixed-40.bmw \
+                            --algorithm block_max_wand \
+                            -k 1000 \
+                            --scorer quantized \
+                            --weighted \
+                            --queries queries/$level/$size.pisa.ints
+
+```
+
diff --git a/src/indexing/inverted_index.py b/src/indexing/inverted_index.py
index 3698089..6a526e4 100644
--- a/src/indexing/inverted_index.py
+++ b/src/indexing/inverted_index.py
@@ -14,7 +14,7 @@
 
 
 class IndexDictOfArray:
-    def __init__(self, index_path=None, force_new=False, filename="array_index.h5py", dim_voc=None):
+    def __init__(self, index_path=None, force_new=True, filename="array_index.h5py", dim_voc=None):
         if index_path is not None:
             self.index_path = index_path
             if not os.path.exists(index_path):
diff --git a/src/tasks/base/trainer.py b/src/tasks/base/trainer.py
index 0058ff9..fc50f59 100644
--- a/src/tasks/base/trainer.py
+++ b/src/tasks/base/trainer.py
@@ -66,8 +66,7 @@ def __init__(self, model, loss, optimizer, config, train_loader, validation_loss
                 self.saver = ValidationSaver(loss=True if self.config["monitoring_ckpt"] == "loss" else False)
                 self.val_decision = "loss" if self.config["monitoring_ckpt"] == "loss" else self.config[
                     "monitoring_ckpt"]
-        self.overwrite_final = config["monitoring_ckpt"]["overwrite_final"] if "overwrite_final" in config[
-            "monitoring_ckpt"] else False
+        self.overwrite_final = config["overwrite_final"] if "overwrite_final" in config else False
         self.training_res_handler = open(os.path.join(self.checkpoint_dir, "training_perf.txt"), "a")
         # => text file in which we record some training perf
         if self.validation: