Accelerator Memory Reuse in the Dark Silicon Era

Accelerators integrated on-die with General-Purpose CPUs (GP-CPUs) can yield significant performance and power improvements. Their extensive use, however, is ultimately limited by their area overhead; due to their high degree of specialization, the opportunity cost of investing die real estate on accelerators can become prohibitive, especially for general-purpose architectures. In this paper we present a novel technique aimed at mitigating this opportunity cost by allowing GP-CPU cores to reuse accelerator memory as a non-uniform cache architecture (NUCA) substrate. On a system with a last level-2 cache of 128kB, our technique achieves on average a 25% performance improvement when reusing four 512 kB accelerator memory blocks to form a level-3 cache. Making these blocks reusable as NUCA slices incurs on average in a 1.89% area overhead with respect to equally-sized ad hoc cache slice

Hyperhomocysteinemia in ankylosing spondylitis: Prevalence and association with clinical variables

We evaluated the prevalence and characteristics associated with hyperhomocysteinemia in ankylosing spondylitis (AS). Ninety-seven patients with AS were compared with 97 controls. The assessment included clinical characteristics, disease activity (BASDAI), functioning (BASFI), history of drugs, and erythrocyte sedimentation rate (ESR). Total serum homocysteine (tHcy) was determined by fluorescence polarization immunoassay. A higher frequency of hyperhomocysteinemia (>15 μmol/L) was observed in AS (12 vs. 1%, P = 0.002). In the multivariate analysis the risk for hyperhomocysteinemia was increased in patients with higher score of HAQ-S (OR = 5.27, 95% CI: 1.29-21.44) and higher ESR (OR = 1.09, 95% CI: 1.02-1.18). No statistical associations was observed between hyperhomocysteinemia with other variables including methotrexate or sulfasalazine utilization. In conclusion, this study found a significant prevalence of hyperhomocysteinemia in Mexican patients with AS mainly associated to a worst functional impairment. Further follow-up studies are required to evaluate the risk of cardiovascular disease in these patients. © 2008 Springer-Verlag